By David Shepardson WASHINGTON (Reuters) -Boeing Co said on Thursday it had resumed flight testing of its 777X jets after an inspection in October found an engine issue. GE said last month it was reviewing a technical issue that occurred during GE9X post-certification engineering testing of the plane, and had decided with Boeing to remove the engine and send it to a test facility in Ohio for engineering test runs. The 777X, also known as the 777-9, is a larger version of the 777 wide-body jet and has been in development since 2013. Boeing in April said it was halting production of the 777X thr…