Fix deprecation warning with pacman on Archlinux.

Author: geerlingguy

tasks/setup-Archlinux.yml

@@ -3,8 +3,7 @@
   pacman: "name=mysql-python state=present"
 
 - name: Ensure MySQL packages are installed.
-  pacman: "name={{ item }} state=present"
-  with_items: "{{ mysql_packages }}"
+  pacman: "name={{ mysql_packages }} state=present"
   register: arch_mysql_install_packages
 
 - name: Run mysql_install_db if MySQL packages were changed.