Don't load development apps if they are already loaded.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/settings/development.py

@@ -9,10 +9,15 @@ DEBUG = True
 CELERY_ALWAYS_EAGER = True
 CELERY_EAGER_PROPAGATES_EXCEPTIONS = CELERY_ALWAYS_EAGER
 
-INSTALLED_APPS += (
-    'rosetta',
-    'django_extensions',
-)
+if 'rosetta' not in INSTALLED_APPS:
+    INSTALLED_APPS += (
+        'rosetta',
+    )
+
+if 'django_extensions' not in INSTALLED_APPS:
+    INSTALLED_APPS += (
+        'django_extensions',
+    )
 
 TEMPLATES[0]['OPTIONS']['loaders'] = (
     'django.template.loaders.filesystem.Loader',