Merge #2066

2066: Upgrade rspamd r=mergify[bot] a=nextgens

## What type of PR?

enhancement

## What does this PR do?

Upgrade rspamd to a version that hopefully won't segfault on arm

### Related issue(s)
- #1200


Co-authored-by: Florent Daigniere <nextgens@freenetproject.org>

core/rspamd/Dockerfile

@@ -1,4 +1,4 @@
-ARG DISTRO=alpine:3.14.2
+ARG DISTRO=alpine:3.15
 FROM $DISTRO
 
 ENV TZ Etc/UTC

core/rspamd/conf/headers_group.conf

@@ -0,0 +1,7 @@
+symbols = {
+    "RCVD_NO_TLS_LAST" {
+	# see https://github.com/Mailu/Mailu/issues/1705
+        weight = 0.0;
+        description = "Last hop did not use encrypted transports";
+    }
+}

core/rspamd/conf/settings.conf

@@ -1,4 +0,0 @@
-apply {
-	# see https://github.com/Mailu/Mailu/issues/1705
-	RCVD_NO_TLS_LAST = 0;
-}