Use yunohost repository for rspamd package on ARMv7

The stock rspamd package provided by Raspbian (jessie) is at version 0.6.10.  The rspamd repository doesn't offer binaries for the armhf architecture (e.g., Raspberry Pi 3) in order to get a more recent package.  Instead, use the yunohost repository for rspamd package (currently at 1.3.5) on armhf.

roles/mailserver/tasks/rspamd.yml

 
 - name: Ensure repository key for Rspamd is in place
   apt_key: url=https://rspamd.com/apt-stable/gpg.key state=present
+  when: ansible_architecture != "armv7l"
+  tags:
+    - dependencies
+
+- name: Ensure yunohost repository key for Rspamd is in place for ARM
+  apt_key: url=http://repo.yunohost.org/debian/yunohost.asc state=present
+  when: ansible_architecture == "armv7l"
   tags:
     - dependencies
 
 - name: Add Rspamd repository
   apt_repository: repo="deb https://rspamd.com/apt-stable/ {{ ansible_distribution_release }} main"
+  when: ansible_architecture != "armv7l"
+  tags:
+    - dependencies
+
+- name: Add yunohost Rspamd repository for ARM
+  apt_repository: repo="deb http://repo.yunohost.org/debian {{ ansible_distribution_release }} stable"
+  when: ansible_architecture == "armv7l"
   tags:
     - dependencies