Replace for-each-in loop with for-of

[cpeterso]

SpiderMonkey's non-standard for-each-in loops have been removed in the Firefox Nightly channel (only) by bug 1293305.

  Message: SyntaxError: missing ( after for
  Stack:
    @resource://jid0-szimol45ib8oddgoubg0buqmjec-at-jetpack/lib/main.js:17:undefined
run@resource://gre/modules/commonjs/sdk/addon/runner.js:147:19
startup/</<@resource://gre/modules/commonjs/sdk/addon/runner.js:87:9
Handler.prototype.process@resource://gre/modules/Promise-backend.js:932:23
this.PromiseWalker.walkerLoop@resource://gre/modules/Promise-backend.js:813:7
Promise*this.PromiseWalker.scheduleWalkerLoop@resource://gre/modules/Promise-backend.js:744:11
this.PromiseWalker.schedulePromise@resource://gre/modules/Promise-backend.js:776:7
this.PromiseWalker.completePromise@resource://gre/modules/Promise-backend.js:711:7
handler@resource://gre/modules/commonjs/sdk/addon/window.js:56:3
EventListener.handleEvent*EventTargetInterposition.methods.addEventListener@resource://gre/modules/RemoteAddonsParent.jsm:644:5
AddonInterpositionService.prototype.interposeProperty/desc.value@jar:file:///Applications/Nightly.app/Contents/Resources/omni.ja!/components/multiprocessShims.js:159:52
@resource://gre/modules/commonjs/sdk/addon/window.js:54:1
startup/<@resource://gre/modules/commonjs/sdk/addon/runner.js:72:21
Handler.prototype.process@resource://gre/modules/Promise-backend.js:932:23
this.PromiseWalker.walkerLoop@resource://gre/modules/Promise-backend.js:813:7
Promise*this.PromiseWalker.scheduleWalkerLoop@resource://gre/modules/Promise-backend.js:744:11
this.PromiseWalker.schedulePromise@resource://gre/modules/Promise-backend.js:776:7
this.PromiseWalker.completePromise@resource://gre/modules/Promise-backend.js:711:7
listener/<@resource://gre/modules/sdk/system/Startup.js:52:46

[autonome]

THANKS!!