Remove -rc.n suffix from coffeescript version.

Now that coffeescript is in packages/non-core, we can publish it
separately from the Meteor release, so it doesn't need a prerelease
version suffix.

packages/non-core/coffeescript/package.js

@@ -1,6 +1,6 @@
 Package.describe({
   summary: "Javascript dialect with fewer braces and semicolons",
-  version: "1.12.3-1-rc.4"
+  version: "1.12.3_1"
 });
 
 Package.registerBuildPlugin({