Matrix: up nginx client_max_body_size to 50MB

Then it's consistent with max_upload_size (sort of - modulo overhead in
http)

roles/docker/files/configs/matrix/vhost-matrix

@@ -1 +1,2 @@
-listen 8008;
+listen 8008;
+client_max_body_size 50M; # default is 1M

roles/docker/files/configs/matrix/vhost-riot

@@ -0,0 +1 @@
+client_max_body_size 50M; # default is 1M

roles/docker/tasks/services/matrix_riot.yml

@@ -46,6 +46,11 @@
     src: files/configs/matrix/vhost-matrix
     dest: "{{ nginx.volume_folder }}/vhost/{{ matrix.domain }}"
 
+- name: upload vhost config for riot domain
+  template:
+    src: files/configs/matrix/vhost-riot
+    dest: "{{ nginx.volume_folder }}/vhost/{{ domain.domain }}"
+
 - name: upload homeserver.yaml
   template:
     src: "files/configs/matrix/homeserver.yaml"