Only define strncasecmp to _strnicmp when using MS compiler.

Redefining strncasecmp to _strnicmp makes libvncclient hang forever in
SetFormatAndEncodings() on Windows when built with MinGW64.

Reported by Tobias Doerffel <tobias.doerffel@gmail.com>, thanks!

libvncclient/rfbproto.c

@@ -31,13 +31,9 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
-#else
-#define strncasecmp _strnicmp
-#endif
-#include <errno.h>
-#ifndef WIN32
 #include <pwd.h>
 #endif
+#include <errno.h>
 #include <rfb/rfbclient.h>
 #ifdef LIBVNCSERVER_HAVE_LIBZ
 #include <zlib.h>

rfb/rfbproto.h

@@ -74,6 +74,11 @@
 #define LIBVNCSERVER_WORDS_BIGENDIAN
 #endif
 
+/* MS compilers don't have strncasecmp */
+#ifdef _MSC_VER
+#define strncasecmp _strnicmp
+#endif
+
 #if !defined(WIN32) || defined(__MINGW32__)
 #define max(a,b) (((a)>(b))?(a):(b))
 #ifdef LIBVNCSERVER_HAVE_SYS_TIME_H