Negative seqno need to be considered when comparing seqno

Need to consider Negative seqno to compare in some cases,
but the task does not support to do that, we need to make it work.

1.we use mariabackup to restore datas on control1, delete the
mariadb data on control2 and control3, and then use cluster recovery,
 as a result that the seqno of the other two nodes will be '-1'.

2. add one more control node into our existing mariadb cluster,
and then use cluster recovery, the seqno of the new node will be '-1'.

Change-Id: Ic1ac8656f28c3835e091637014f075ac5479d390
(cherry picked from commit 068f3fe)

Author: fudunwei

ansible/roles/mariadb/tasks/recover_cluster.yml

@@ -74,7 +74,7 @@
       shell:
         cmd: |
           if [[ ! -z {{ hostvars[inventory_hostname]['seqno'] }} && ! -z {{ hostvars[item]['seqno'] }} &&
-          {{ hostvars[inventory_hostname]['seqno'] }} =~ ^[0-9]+$ && {{ hostvars[item]['seqno'] }} =~ ^[0-9]+$ &&
+          {{ hostvars[inventory_hostname]['seqno'] }} =~ ^-?[0-9]+$ && {{ hostvars[item]['seqno'] }} =~ ^-?[0-9]+$ &&
           {{ hostvars[inventory_hostname]['seqno'] }} -lt {{ hostvars[item]['seqno'] }} ]]; then echo {{ hostvars[item]['seqno'] }}; fi
       with_items: "{{ groups['mariadb'] }}"
       register: seqno_compare