TF-912: Support rich text for signature htmlBody of identity

pubspec.yaml

@@ -45,7 +45,7 @@ dependencies:
   rich_text_composer:
     git:
       url: https://github.com/linagora/rich-text-composer.git
-      ref: apply_rich_text_bottom_sheet
+      ref: master
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
@@ -143,11 +143,6 @@ dependencies:
       url: https://github.com/linagora/html-editor-enhanced.git
       ref: email_supported
 
-  rich_text_composer:
-    git:
-      url: https://github.com/linagora/rich-text-composer.git
-      ref: master
-
   # fk_user_agent
   fk_user_agent: 2.1.0