roles/mariadb: Add missing mariadb_users.root password. Also make the task no_log: true

group_vars/all/mariadb.yml

+$ANSIBLE_VAULT;1.1;AES256
+37663663326439323533653639626666616338653062643234363233363731643964323865326534
+6333393164393664393865336139346535643664643338390a633264653039343663326361666165
+32346336366464373361326234616131306433336163616165343263376533363061343263666361
+6239343631336136660a336136323864373331386232363739343962336538383431353839643561
+66646336343061633934633864393464303336613662663363643762396235306438316531663234
+65346336393831643066613931613661643731313831346536646130373937386364356261393739
+633336633636373438653563653533656337

roles/mariadb/tasks/main.yml

@@ -28,6 +28,7 @@
     - '127.0.0.1'
     - '::1'
     - 'localhost'
+  no_log: true
 
 - name: create client configuration for root
   template: src=client.cnf.j2 dest=/root/.my.cnf