Remove parentheses from if statement

Otherwise Rubocop will give a warning.

As mentioned in !3197.

app/services/git_push_service.rb

@@ -89,7 +89,7 @@ class GitPushService < BaseService
     project.change_head(branch_name)
 
     # Set protection on the default branch if configured
-    if (current_application_settings.default_branch_protection != PROTECTION_NONE)
+    if current_application_settings.default_branch_protection != PROTECTION_NONE
       developers_can_push = current_application_settings.default_branch_protection == PROTECTION_DEV_CAN_PUSH ? true : false
       @project.protected_branches.create({ name: @project.default_branch, developers_can_push: developers_can_push })
     end