fix(location): check for existence before using

[eddiemonge]

Check to see if the value exists before attempting to use it to avoid throwing unnecessary errors

Partially fixes #4442

[mary-poppins]

Thanks for the PR!

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Thanks again for your help!

[eddiemonge]

Is it possible to have @mary-poppins auto check the cla list and update its message based on that?

[petebacondarwin]

@eddiemonge - sorry Mary isn't allowed to see the CLA list yet. It is an internal Google document.

[petebacondarwin]

@eddiemonge - This fix will need a unit test to demonstrate the issue before it can be merged.

[petebacondarwin]

@eddiemonge - Actually this is not an appropriate fix. beginsWith should not be passed undefined in the url parameter and neither should $$parse. The real problem in #4442 is that $$rewrite should never be returning undefined.