Only define ZLIB_SHARED if it hasn't already been defined (on the command

line, for example).

PR: 1112

crypto/comp/c_zlib.c

@@ -73,7 +73,9 @@ static COMP_METHOD zlib_stateful_method={
 # include <windows.h>
 
 # define Z_CALLCONV _stdcall
-# define ZLIB_SHARED
+# ifndef ZLIB_SHARED
+#  define ZLIB_SHARED
+# endif
 #else
 # define Z_CALLCONV
 #endif /* !(OPENSSL_SYS_WINDOWS || OPENSSL_SYS_WIN32) */