Bumping gaia.json for 1 gaia-central revision(s)

========

https://hg.mozilla.org/integration/gaia-central/rev/0b154cf02504
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Revert "Merge pull request #12000 from nullaus/operator-variant"

This reverts commit cfcea746250d7c6ea01a389c3d7714c471f28641, reversing
changes made to ba071b88afd06682117b194a6cccc5cb2d6d7a48.

Reverting because it is failing a unit test

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "c95dc10d3f8556a900c398431f6255521bbfa4a3", 
+    "revision": "0b154cf0250488320f7569649eaaf69ed5a209a4", 
     "repo_path": "/integration/gaia-central"
 }