cmake: Pacify warning about Policy CMP0042 not being set.

CMakeLists.txt

@@ -170,6 +170,7 @@ endif()
 option(PHYSFS_BUILD_SHARED "Build shared library" TRUE)
 if(PHYSFS_BUILD_SHARED)
     add_library(physfs SHARED ${PHYSFS_SRCS})
+    set_target_properties(physfs PROPERTIES MACOSX_RPATH 1)
     set_target_properties(physfs PROPERTIES VERSION ${PHYSFS_VERSION})
     set_target_properties(physfs PROPERTIES SOVERSION ${PHYSFS_SOVERSION})
     if(WINRT)