Bug 1154356 needs a CLOBBER for good measure

CLOBBER

@@ -22,7 +22,4 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Bug 1038068: Check add-on signatures and refuse to install unsigned or broken add-ons
-
-Not sure why this needs a clobber but tests perma-failed when they don't on
-try (2).
+Bug 1154356: escape variable name in Declaration::AppendVariableAndValueToString;