#1552 Rosegarden fails to build with cmake-3.9.0

[Dave Plater]

openSUSE:Factory has just updated to cmake-3.9.0 and rosegarden fails to build with it. I've opened a ticket https://gitlab.kitware.com/cmake/cmake/issues/17222 as it appears to be a cmake bug involving
No rule to make target 'src/svnversion.h', needed by 'src/CMakeFiles/rosegardenprivate_autogen'
I've worked around the problem using "make svnheader" prior to the main make.

[Stuart Prescott]

The dependency for ordering the creation of svnversion.h appears to be incorrect and CMake 3.9 apparently does not order the build in the same way as previous CMakes so that this failure to build is now exposed with parallel builds. The attached patch seems to work fine.

[Dave Plater]

Can confirm this fixes the build.

[Yves Guillemot]

I currently only run cmake 3.7.2 and the patch doesn't break the build with it.
So I presume it doesn't break other old cmake versions (which I can't test) and I'm going to commit it.
Thanks to Dave Plater for reporting and to Stuart Prescott for the patch.

[Dave Plater]

In fact openSUSE 42.2 has cmake-3.5.2 and it builds fine there with the patch in place.

[Yves Guillemot]

Done in [r15089]