build script: update flac target

add linking with ogg library to .pc file
do not build c++ library

.gitignore

@@ -9,8 +9,6 @@
 /deps/bzip2/bin/
 /deps/bzip2/man/
 /deps/flac/bin/
-/deps/flac/include/FLAC++/
-/deps/flac/lib/libFLAC++.a
 /deps/iconv/bin/
 /deps/iconv/include/*charset.h
 /deps/iconv/lib/libcharset.a

build.py

@@ -688,6 +688,8 @@ class FfiTarget(ConfigureMakeStaticDependencyTarget):
 class FlacTarget(ConfigureMakeStaticDependencyTarget):
     def __init__(self, name='flac'):
         super().__init__(name)
+        self.options['--enable-cpplibs'] = 'no'
+        self.pkg_libs = {'flac': '-logg'}
 
     def prepare_source(self, builder: 'Builder'):
         builder.download_source(