playbook/imt-slapos: default number of partition is 125

Since re6st is giving a /25 subnetwork to the machine and address 1 is
assigned to the host by re6st, it means we have only 125 addresses left
for tap interfaces.

playbook/roles/imt-slapos/tasks/main.yml

@@ -52,7 +52,7 @@
     with_items:
       - { regexp: '^create_tap\s*=', line: 'create_tap = True' }
       - { regexp: '^tap_gateway_interface\s*=', line: 'tap_gateway_interface = re6stnet-tcp' }
-      - { regexp: '^partition_amount\s*=', line: 'partition_amount = 126' }
+      - { regexp: '^partition_amount\s*=', line: 'partition_amount = 125' }
       - { regexp: '^tap_ipv6\s*=', line: 'tap_ipv6 = False' }
     when: post_config is defined and slapos_cfg.stat.exists == True and startup is not defined