MINOR: snapshot: restart on the event ID and not the stream ID

The snapshots have the ability to restart a partial dump and they use
the stream ID as the restart point. Since it's purely HTTP, let's use
the event ID instead.
diff --git a/include/types/applet.h b/include/types/applet.h
index d4172bd..3890860 100644
--- a/include/types/applet.h
+++ b/include/types/applet.h
@@ -132,7 +132,7 @@
 			int iid;		/* if >= 0, ID of the proxy to filter on */
 			struct proxy *px;	/* current proxy being dumped, NULL = not started yet. */
 			unsigned int flag;	/* bit0: buffer being dumped, 0 = req, 1 = resp ; bit1=skip req ; bit2=skip resp. */
-			unsigned int sid;	/* session ID of error being dumped */
+			unsigned int ev_id;	/* event ID of error being dumped */
 			int ptr;		/* <0: headers, >=0 : text pointer to restart from */
 			int bol;		/* pointer to beginning of current line */
 		} errors;
diff --git a/src/proto_http.c b/src/proto_http.c
index cf759fb..b6d429b 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -12784,10 +12784,10 @@
 				return 0;
 			}
 			appctx->ctx.errors.ptr = 0;
-			appctx->ctx.errors.sid = es->sid;
+			appctx->ctx.errors.ev_id = es->ev_id;
 		}
 
-		if (appctx->ctx.errors.sid != es->sid) {
+		if (appctx->ctx.errors.ev_id != es->ev_id) {
 			/* the snapshot changed while we were dumping it */
 			chunk_appendf(&trash,
 				     "  WARNING! update detected on this snapshot, dump interrupted. Please re-check!\n");