18.05 doesn't build with MLT 6.6.0

Bug
1

18.05 uses mlt_channel_layout_default() and mlt_channel_layout_name() only available in MLT git.

widgets/avformatproducerwidget.cpp: In member function ‘void vformatProducerWidget::onFrameDisplayed(const SharedFrame&)’:
widgets/avformatproducerwidget.cpp:261:62: error: ‘mlt_channel_layout_default’ was not declared in this scope
                 const char* layout = mlt_channel_layout_name(mlt_channel_layout_default(channels));
                                                              ^~~~~~~~~~~~~~~~~~~~~~~~~~
widgets/avformatproducerwidget.cpp:261:38: error: ‘mlt_channel_layout_name’ was not declared in this scope
                 const char* layout = mlt_channel_layout_name(mlt_channel_layout_default(channels));
                                      ^~~~~~~~~~~~~~~~~~~~~~~
widgets/avformatproducerwidget.cpp:261:38: note: suggested alternative: ‘mlt_cache_put_frame’
                 const char* layout = mlt_channel_layout_name(mlt_channel_layout_default(channels));
                                      ^~~~~~~~~~~~~~~~~~~~~~~
                                      mlt_cache_put_frame
make[1]: *** [Makefile:2545: avformatproducerwidget.o] Error 1
2

This is not a bug. Shotcut is not required to only use released versions of MLT.

3

I’ve never seen that in 2 years I package shotcut.
The 18.05 release note say nothing about that, when 18.03 release note say that MLT 6.6.0 is required.

Certainly a mistake in 18.05 for me as software should not use unreleased third party software.