contrib: gmp: fix duplicate symbol definitions in gnutls

contrib/src/gmp/inline.diff

+--- gmp-4.2.1/gmp-h.in.orig	2013-03-26 14:53:42.132617397 +0100
++++ gmp-4.2.1/gmp-h.in	2013-03-26 14:53:47.424617630 +0100
+@@ -420,8 +420,7 @@
+    for an inline too, so as to correctly specify "dllimport" on windows, in
+    case the function is called rather than inlined.  */
+ #ifdef __GNUC__
+-#define __GMP_EXTERN_INLINE      extern __inline__
+-#define __GMP_INLINE_PROTOTYPES  1
++#define __GMP_EXTERN_INLINE      static __inline__
+ #endif
+ 
+ /* DEC C (eg. version 5.9) supports "static __inline foo()", even in -std1

contrib/src/gmp/rules.mak

@@ -13,6 +13,7 @@ $(TARBALLS)/gmp-$(GMP_VERSION).tar.bz2:
 
 gmp: gmp-$(GMP_VERSION).tar.bz2 .sum-gmp
 	$(UNPACK)
+	$(APPLY) $(SRC)/gmp/inline.diff
 	$(UPDATE_AUTOCONFIG)
 	$(MOVE)