roles/ipaclient/tasks/install.yml: Allow to specify different hostname

ipaclient_hostname needs to be specified in the inventory file for the hosts
where the name needs to get changed.

Example:
192.168.1.1 ipaclient_hostname=ipaclient1.mine.local

The option should not be specified in [ipaclients:vars] as all hosts would
get the same name.

roles/ipaclient/tasks/install.yml

@@ -16,7 +16,7 @@
     domain: "{{ ipaclient_domain | default(omit) }}"
     servers: "{{ groups.ipaservers | default(omit) }}"
     realm: "{{ ipaclient_realm | default(omit) }}"
-    hostname: "{{ ansible_fqdn }}"
+    hostname: "{{ ipaclient_hostname | default(ansible_fqdn) }}"
     #ca_cert_file: "{{ ipaclient_ca_cert_file | default(omit) }}"
     check: yes
   register: ipadiscovery