MINOR: filters/http-ana: Decide to filter HTTP headers in HTTP analysers

It is just a small cleanup. AN_REQ_FLT_HTTP_HDRS and AN_RES_FLT_HTTP_HDRS
analysers are now set in HTTP analysers at the same place
AN_REQ_HTTP_XFER_BODY and AN_RES_HTTP_XFER_BODY are set.
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 0cffdbb..2682fba 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -3207,10 +3207,6 @@
 			if (!LIST_ISEMPTY(&curproxy->filter_configs)) {
 				curproxy->fe_req_ana |= AN_REQ_FLT_START_FE | AN_REQ_FLT_XFER_DATA | AN_REQ_FLT_END;
 				curproxy->fe_rsp_ana |= AN_RES_FLT_START_FE | AN_RES_FLT_XFER_DATA | AN_RES_FLT_END;
-				if (curproxy->mode == PR_MODE_HTTP) {
-					curproxy->fe_req_ana |= AN_REQ_FLT_HTTP_HDRS;
-					curproxy->fe_rsp_ana |= AN_RES_FLT_HTTP_HDRS;
-				}
 			}
 		}
 
@@ -3237,10 +3233,6 @@
 			if (!LIST_ISEMPTY(&curproxy->filter_configs)) {
 				curproxy->be_req_ana |= AN_REQ_FLT_START_BE | AN_REQ_FLT_XFER_DATA | AN_REQ_FLT_END;
 				curproxy->be_rsp_ana |= AN_RES_FLT_START_BE | AN_RES_FLT_XFER_DATA | AN_RES_FLT_END;
-				if (curproxy->mode == PR_MODE_HTTP) {
-					curproxy->be_req_ana |= AN_REQ_FLT_HTTP_HDRS;
-					curproxy->be_rsp_ana |= AN_RES_FLT_HTTP_HDRS;
-				}
 			}
 		}
 
diff --git a/src/http_ana.c b/src/http_ana.c
index a13c946..b0067c3 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -452,6 +452,9 @@
 		if (!(s->flags & SF_FINST_MASK))
 			s->flags |= SF_FINST_R;
 
+		if (HAS_FILTERS(s))
+			req->analysers |= AN_REQ_FLT_HTTP_HDRS;
+
 		/* enable the minimally required analyzers to handle keep-alive and compression on the HTTP response */
 		req->analysers &= (AN_REQ_HTTP_BODY | AN_REQ_FLT_HTTP_HDRS | AN_REQ_FLT_END);
 		req->analysers &= ~AN_REQ_FLT_XFER_DATA;
@@ -777,6 +780,12 @@
 		}
 	}
 
+	/* Filter the request headers if there are filters attached to the
+	 * stream.
+	 */
+	if (HAS_FILTERS(s))
+		req->analysers |= AN_REQ_FLT_HTTP_HDRS;
+
 	/* If we have no server assigned yet and we're balancing on url_param
 	 * with a POST request, we may be interested in checking the body for
 	 * that parameter. This will be done in another analyser.
@@ -2071,6 +2080,12 @@
 	if (!http_eval_after_res_rules(s))
 		goto return_int_err;
 
+	/* Filter the response headers if there are filters attached to the
+	 * stream.
+	 */
+	if (HAS_FILTERS(s))
+		rep->analysers |= AN_RES_FLT_HTTP_HDRS;
+
 	/* Always enter in the body analyzer */
 	rep->analysers &= ~AN_RES_FLT_XFER_DATA;
 	rep->analysers |= AN_RES_HTTP_XFER_BODY;
diff --git a/src/proxy.c b/src/proxy.c
index 234515d..d044150 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -2153,11 +2153,6 @@
 		http_init_txn(s);
 	}
 
-	/* Be sure to filter request headers if the backend is an HTTP proxy and
-	 * if there are filters attached to the stream. */
-	if (s->be->mode == PR_MODE_HTTP && HAS_FILTERS(s))
-		s->req.analysers |= AN_REQ_FLT_HTTP_HDRS;
-
 	if (s->txn) {
 		/* If we chain a TCP frontend to an HTX backend, we must upgrade
 		 * the client mux */
diff --git a/src/stream.c b/src/stream.c
index c1ba905..eb64807 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -933,11 +933,6 @@
 
 	rep->analysers |= strm_fe(s)->fe_rsp_ana | s->be->be_rsp_ana;
 
-	/* Be sure to filter response headers if the backend is an HTTP proxy
-	 * and if there are filters attached to the stream. */
-	if (IS_HTX_STRM(s) && HAS_FILTERS(s))
-		rep->analysers |= AN_RES_FLT_HTTP_HDRS;
-
 	si_rx_endp_more(si);
 	rep->flags |= CF_READ_ATTACHED; /* producer is now attached */
 	if (objt_cs(si->end)) {