Merge pull request #3268 from libgit2/vmg/pkg-config-sort

pkg-config: Sort the different sections

libgit2.pc.in

@@ -4,7 +4,9 @@ includedir=@CMAKE_INSTALL_PREFIX@/@INCLUDE_INSTALL_DIR@
 Name: libgit2
 Description: The git library, take 2
 Version: @LIBGIT2_VERSION_STRING@
-Requires.private: @LIBGIT2_PC_REQUIRES@
-Libs.private: @LIBGIT2_PC_LIBS@
+
 Libs: -L${libdir} -lgit2
+Libs.private: @LIBGIT2_PC_LIBS@
+Requires.private: @LIBGIT2_PC_REQUIRES@
+
 Cflags: -I${includedir}