Fix passkey.pem permissions breaking IRC bridge

Regression since 174a6fcd1b3, #204 (Github Pull Request),
which only affects new servers.

Old servers which had their passkey.pem file relocated were okay.

roles/matrix-bridge-appservice-irc/tasks/setup_install.yml

@@ -59,8 +59,19 @@
 
 - name: Generate Appservice IRC passkey if it doesn't exist
   shell: /usr/bin/openssl genpkey -out {{ matrix_appservice_irc_data_path }}/passkey.pem -outform PEM -algorithm RSA -pkeyopt rsa_keygen_bits:2048
+  become: true
+  become_user: "{{ matrix_user_username }}"
   when: "not irc_passkey_file.stat.exists"
 
+# In the past, we used to generate the passkey.pem file with root, so permissions may not be okay.
+# Fix it.
+- name: (Migration) Ensure Appservice IRC passkey permissions are okay
+  file:
+    path: "{{ matrix_appservice_irc_data_path }}/passkey.pem"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_username }}"
+
 # Ideally, we'd like to generate the final registration.yaml file by ourselves.
 #
 # However, the IRC bridge supports multiple servers, which leads to multiple