Make sure we don't pick up libdispatch if available

Else it may fail in bulk builds.  Using libdispatch might be desirable
but that needs testing first.  Bump REVISION to avoid leaving incorrect
packages on users machines.

Spotted by naddy when building x11/gnustep/base a few days ago.

x11/gnustep/libobjc2/Makefile

@@ -9,7 +9,7 @@ GH_PROJECT =	libobjc2
 GH_TAGNAME =	v${VERSION}
 DISTNAME =	libobjc2-${VERSION:S/_//}
 PKGNAME =	gnustep-${DISTNAME}
-REVISION =	5
+REVISION =	6
 
 SHARED_LIBS +=	objc2	1.1
 SHARED_LIBS +=  objcxx	0.0

x11/gnustep/libobjc2/patches/patch-CMakeLists_txt

@@ -1,4 +1,5 @@
 Do not use CMAKE_THREAD_LIBS_INIT as linker flag
+Don't pick up libdispatch if available.
 
 Index: CMakeLists.txt
 --- CMakeLists.txt.orig
@@ -35,7 +36,20 @@ Index: CMakeLists.txt
  
  # Explicitly link the C++ runtime and libgc if we are compiling with gc support.
  target_link_libraries(objc ${CXX_RUNTIME})
-@@ -285,6 +283,11 @@ if (APPLE)
+@@ -272,12 +270,6 @@ if (LIBGC)
+ 	target_link_libraries(objc ${LIBGC})
+ endif ()
+ 
+-# Link libdispatch if available (we'll miss symbols for toydispatch otherwise)
+-find_library(LIBDISPATCH dispatch)
+-if (LIBDISPATCH)
+-	target_link_libraries(objc ${LIBDISPATCH})
+-endif ()
+-
+ # Make weak symbols work on OS X
+ if (APPLE)
+ 	set(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS
+@@ -285,6 +277,11 @@ if (APPLE)
  	set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} -Wl,-undefined,dynamic_lookup")
  	set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} -Wl,-undefined,dynamic_lookup")
  endif ()