app/matrix: reflect current production status

At some point someone bumped appservice-irc to 0.17.1 without commiting
this to git. This fixes that, and also drive-by refactors the
appservice-irc image version to live next to all the other version
strings.

`kubecfg diff --diff-strategy=subset prod.jsonnet` now shows no diff.

Change-Id: I90a64d05cc72669de41fa68195672adca2eb37e8
diff --git a/app/matrix/prod.jsonnet b/app/matrix/prod.jsonnet
index e9d43be..d6e3c26 100644
--- a/app/matrix/prod.jsonnet
+++ b/app/matrix/prod.jsonnet
@@ -18,7 +18,8 @@
 
         synapseImage: "matrixdotorg/synapse:v1.11.1",
         riotImage: "vectorim/riot-web:v1.5.13",
-        casProxyImage: "registry.k0.hswaw.net/q3k/oauth2-cas-proxy:0.1.4"
+        casProxyImage: "registry.k0.hswaw.net/q3k/oauth2-cas-proxy:0.1.4",
+        appserviceIRCImage: "matrixdotorg/matrix-appservice-irc:release-0.17.1",
     },
 
     metadata(component):: {
@@ -278,7 +279,7 @@
         local bridge = self,
         local cfg = bridge.cfg,
         cfg:: {
-            image: "matrixdotorg/matrix-appservice-irc:release-0.16.0",
+            image: app.cfg.appserviceIRCImage,
             metadata: {},
             config: std.native("parseYaml")(importstr "appservice-irc.yaml")[0],
             storageClassName: app.cfg.storageClassName,