Don't use pkg-config to find libgit2

This may be wrong, but turning off pkg-config in FindLibgit2.cmake
makes cmake respect library paths given from the command line (with -D)

Author: charypar

CMake/FindLibgit2.cmake

@@ -9,8 +9,8 @@
 
 # use pkg-config to get the directories and then use these values
 # in the FIND_PATH() and FIND_LIBRARY() calls
-FIND_PACKAGE(PkgConfig)
-PKG_SEARCH_MODULE(PC_LIBGIT2 libgit2)
+#FIND_PACKAGE(PkgConfig)
+#PKG_SEARCH_MODULE(PC_LIBGIT2 libgit2)
 
 SET(LIBGIT2_DEFINITIONS ${PC_LIBGIT2_CFLAGS_OTHER})