Issue 4697 - Add support for WebExtension-based Firefox development builds

sitescripts/extensions/bin/updateUpdateManifests.py

Index: sitescripts/extensions/bin/updateUpdateManifests.py
===================================================================
--- a/sitescripts/extensions/bin/updateUpdateManifests.py
+++ b/sitescripts/extensions/bin/updateUpdateManifests.py
@@ -117,17 +117,18 @@ def writeUpdateManifest(links):
         else:
             # ABP for Android used to have its own update manifest format. We need to
             # generate both that and the new one in the libadblockplus format as long
             # as a significant amount of users is on an old version.
             if repoType == 'android':
                 newManifestPath = get_config().get('extensions',
                                                    'androidNewUpdateManifestPath')
                 writeAndroidUpdateManifest(newManifestPath, extensions[repoType])
-            template = get_template(get_config().get('extensions', '%sUpdateManifest' % repoType))
+            path = get_config().get('extensions', '%sUpdateManifest' % repoType)
+            template = get_template(path, autoescape=not path.endswith('.json'))
             template.stream({'extensions': extensions[repoType]}).dump(manifestPath)
 
 
 def updateUpdateManifests():
     """
     updates all update manifests with the current versions
     """