[WIN32] Fix error on missing time functions.
When building with mingw-w64, I suddently got this error:
[ 52%] Building CXX object src/CMakeFiles/zynaddsubfx_core.dir/Misc/Part.cpp.obj
src/Misc/Part.cpp: In lambda function:
src/Misc/Part.cpp:174:17: error: 'time' was not declared in this scope; did you mean 'ftime'?
174 | time (&rawtime);
| ^~~~
| ftime
src/Misc/Part.cpp:175:45: error: 'localtime' was not declared in this scope
175 | const struct tm* timeinfo = localtime (&rawtime);
| ^~~~~~~~~
src/Misc/Part.cpp:176:17: error: 'strftime' was not declared in this scope; did you mean 'ftime'?
176 | strftime (p->loaded_file,23,"%F_%R.xiz",timeinfo);
| ^~~~~~~~
| ftime
make[2]: *** [src/CMakeFiles/zynaddsubfx_core.dir/build.make:447: src/CMakeFiles/zynaddsubfx_core.dir/Misc/Part.cpp.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:1659: src/CMakeFiles/zynaddsubfx_core.dir/all] Error 2
The solution is to include ctime near the other include files.
I tested it also with Debian and CYGWIN so it should be fine