Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/b86ee9e343bb
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #15681 from julienw/959422-fix-crashing-canvases

Bug 959422 - [Messages] The Messages app crashes when attaching too big images

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https://hg.mozilla.org/integration/gaia-central/rev/eb07f5ac1a2a
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 959422 - [Messages] The Messages app crashes when attaching too big images r=gsvelto

This adds willReadFrequently to all our canvas contexts that are not displayed.

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "200c6030f6f71608f2fff0c0922fda3397d86f3b", 
+    "revision": "b86ee9e343bb29b35426844ab689ad8bb0ea787d", 
     "repo_path": "/integration/gaia-central"
 }