Fix support for older versions of OS X (#19)

Author: igrr

local/Makefile.local.OSX

@@ -6,4 +6,4 @@ CXX=clang++
 TARGET_FLAGS	=
 TARGET_CFLAGS   = -mmacosx-version-min=10.6 -arch i386 -arch x86_64
 TARGET_CXXFLAGS = -mmacosx-version-min=10.6 -arch i386 -arch x86_64
-TARGET_LDFLAGS  = -arch i386 -arch x86_64
+TARGET_LDFLAGS  = -mmacosx-version-min=10.6 -arch i386 -arch x86_64