MINOR: stream: report the current filter in "show sess all" when known

Filters can block the stream on pre/post analysis for any reason and it can
be useful to report it in "show sess all". So now, a "current_filter" extra
line is reported for each channel if a filter is blocking the analysis. Note
that this does not catch the TCP/HTTP payload analysis because all
registered filters are always evaluated when more data are received.
diff --git a/src/stream.c b/src/stream.c
index 162dfaa..6d6374d 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -3382,6 +3382,12 @@
 				      (htx->tail >= htx->head) ? "NO" : "YES",
 				      (unsigned long long)htx->extra);
 		}
+		if (HAS_FILTERS(strm) && strm_flt(strm)->current[0]) {
+			struct filter *flt = strm_flt(strm)->current[0];
+
+			chunk_appendf(&trash, "      current_filter=%p (id=\"%s\" flags=0x%x pre=0x%x post=0x%x) \n",
+				      flt, flt->config->id, flt->flags, flt->pre_analyzers, flt->post_analyzers);
+		}
 
 		chunk_appendf(&trash,
 			     "  res=%p (f=0x%06x an=0x%x pipe=%d tofwd=%d total=%lld)\n"
@@ -3420,6 +3426,12 @@
 				      (htx->tail >= htx->head) ? "NO" : "YES",
 				      (unsigned long long)htx->extra);
 		}
+		if (HAS_FILTERS(strm) && strm_flt(strm)->current[1]) {
+			struct filter *flt = strm_flt(strm)->current[1];
+
+			chunk_appendf(&trash, "      current_filter=%p (id=\"%s\" flags=0x%x pre=0x%x post=0x%x) \n",
+				      flt, flt->config->id, flt->flags, flt->pre_analyzers, flt->post_analyzers);
+		}
 
 		if (strm->current_rule_list && strm->current_rule) {
 			const struct act_rule *rule = strm->current_rule;