[package] fetchmail: fixup md5 transition

this patch is cherry-pick from upstream:
  738dcc102d

this patch fixed this error:
  http://tksite.gotdns.org:8010/broken_packages/xburst/fetchmail/compile.txt
~~~
mipsel-openwrt-linux-uclibc-gcc -DHAVE_CONFIG_H -DLOCALEDIR=\"/usr/share/locale\" -I.  -I./libesmtp -I/home/buildslave/openwrt1/xburst/build/staging_dir/target-mipsel_uClibc-0.9.31/usr/include -I/home/buildslave/openwrt1/xburst/build/staging_dir/target-mipsel_uClibc-0.9.31/include -I/home/buildslave/openwrt1/xburst/build/staging_dir/toolchain-mipsel_gcc-4.3.3+cs_uClibc-0.9.31/usr/include -I/home/buildslave/openwrt1/xburst/build/staging_dir/toolchain-mipsel_gcc-4.3.3+cs_uClibc-0.9.31/include   -Os -pipe -mips32 -mtune=mips32 -funit-at-a-time -fhonour-copts -msoft-float  -MT md5c.o -MD -MP -MF .deps/md5c.Tpo -c -o md5c.o md5c.c
md5c.c:44: warning: 'struct MD5Context' declared inside parameter list
md5c.c:44: warning: its scope is only this definition or declaration, which is probably not what you want
md5c.c: In function 'MD5Init':
md5c.c:46: error: dereferencing pointer to incomplete type
md5c.c:47: error: dereferencing pointer to incomplete type
~~~

git-svn-id: svn://svn.openwrt.org/openwrt/packages@25228 3c298f89-4303-0410-b956-a3cf2f4a3e73

mail/fetchmail/patches/001-Fixup-MD5-transition.patch

@@ -0,0 +1,25 @@
+--- a/fm_md5.h
++++ b/fm_md5.h
+@@ -5,16 +5,8 @@
+ 
+ #include <sys/types.h>
+ 
+-#ifdef HAVE_MD5_H
+-#include <md5.h>
+-#else
+ #include "fetchmail.h"
+-#ifndef HEADER_MD5_H
+-/* Try to avoid clashes with OpenSSL */
+-#define HEADER_MD5_H 
+-#endif
+ 
+-
+ #if SIZEOF_INT == 4
+ typedef unsigned int uint32;
+ #else
+@@ -37,6 +29,5 @@
+  */
+ typedef struct MD5Context MD5_CTX;
+ 
+-#endif
+ #endif /* !MD5_H */