Update the ecm diff to not check PyQt version

We use Qt 5.6.1, which isn't in

%Timeline {Qt_5_0_0 Qt_5_0_1 Qt_5_0_2 Qt_5_1_0 Qt_5_1_1 Qt_5_2_0 Qt_5_2_1 Qt_5_3_0 Qt_5_3_1 Qt_5_3_2 Qt_5_4_0 Qt_5_4_1 Qt_5_4_2 Qt_5_5_0 Qt_5_5_1 Qt_5_6_0}

in QtCoremod.sip, even though we build against Qt 5.6.1. Skipping
this check allows us to get started, at least.