Updated mediawiki/extensions
Project: mediawiki/extensions/Flow  69913f7fca039e4bb14f4d7ec5aad4deaee5e509

Use InvalidInputException

The class was incorrectly being called; should've been either
\Flow\... (with leading slash!) or use'd.

Change-Id: I7f3cd6318bf99d902d065e53d56d274fee5af5d1