fix indent to 4 spaces

Author: mayeco

Resources/config/services.yml

@@ -1,10 +1,10 @@
 services:
-  vivait_stringgenerator.generator:
-      class: "%vivait_string_generator.generator_class%"
-      public: false
-  vivait_stringgenerator.generator.listener:
-      class: Vivait\StringGeneratorBundle\EventListener\StringGeneratorListener
-      public: false
-      arguments: ["@annotation_reader", "@vivait_stringgenerator.generator"]
-      tags:
-          - { name: doctrine.event_listener, event: prePersist }
+    vivait_stringgenerator.generator:
+        class: "%vivait_string_generator.generator_class%"
+        public: false
+    vivait_stringgenerator.generator.listener:
+        class: Vivait\StringGeneratorBundle\EventListener\StringGeneratorListener
+        public: false
+        arguments: ["@annotation_reader", "@vivait_stringgenerator.generator"]
+        tags:
+            - { name: doctrine.event_listener, event: prePersist }