ci: switch to drone-matrix plugin

.drone.jsonnet

@@ -132,11 +132,11 @@ local PipelineNotification = {
   steps: [
     {
       name: 'matrix',
-      image: 'plugins/matrix',
+      image: 'thegeeklab/drone-matrix',
       settings: {
         homeserver: { from_secret: 'matrix_homeserver' },
         roomid: { from_secret: 'matrix_roomid' },
-        template: 'Status: **{{ build.status }}**<br/> Build: [{{ repo.Owner }}/{{ repo.Name }}]({{ build.link }}) ({{ build.branch }}) by {{ build.author }}<br/> Message: {{ build.message }}',
+        template: 'Status: **{{ build.Status }}**<br/> Build: [{{ repo.Owner }}/{{ repo.Name }}]({{ build.Link }}){{#if build.Branch}} ({{ build.Branch }}){{/if}} by {{ commit.Author }}<br/> Message: {{ commit.Message.Title }}',
         username: { from_secret: 'matrix_username' },
         password: { from_secret: 'matrix_password' },
       },

.drone.yml

@@ -122,7 +122,7 @@ clone:
 
 steps:
   - name: matrix
-  image: plugins/matrix
+    image: thegeeklab/drone-matrix
     settings:
       homeserver:
         from_secret: matrix_homeserver
@@ -130,7 +130,7 @@ steps:
         from_secret: matrix_password
       roomid:
         from_secret: matrix_roomid
-    template: "Status: **{{ build.status }}**<br/> Build: [{{ repo.Owner }}/{{ repo.Name }}]({{ build.link }}) ({{ build.branch }}) by {{ build.author }}<br/> Message: {{ build.message }}"
+      template: "Status: **{{ build.Status }}**<br/> Build: [{{ repo.Owner }}/{{ repo.Name }}]({{ build.Link }}){{#if build.Branch}} ({{ build.Branch }}){{/if}} by {{ commit.Author }}<br/> Message: {{ commit.Message.Title }}"
       username:
         from_secret: matrix_username
 
@@ -147,6 +147,6 @@ depends_on:
 
 ---
 kind: signature
-hmac: fac78bc551ef3e24afb0345291411a7193ed401426d9698b8ec31d471397ca73
+hmac: a38837478ca0ce8de95ed32fe9f8c247a4086ae63b97fba2db4cf1f8b5ba41c1
 
 ...