Merge pull request #7651 from dnkoutso/more_system_removal

Do not force `[system]` value for custom module maps

(cherry picked from commit 644280b5)

# Conflicts:
#	spec/cocoapods-integration-specs

lib/cocoapods/installer/xcode/pods_project_generator/pod_target_installer.rb

@@ -594,7 +594,7 @@ module Pod
             UI.message "- Copying module map file to #{UI.path(path)}" do
               contents = custom_module_map.read
               unless target.requires_frameworks?
-                contents.gsub!(/^(\s*)framework\s+(module[^{}]+){/, '\1\2[system] {')
+                contents.gsub!(/^(\s*)framework\s+(module[^{}]+){/, '\1\2{')
               end
               generator = Generator::Constant.new(contents)
               update_changed_file(generator, path)