patch 7.4.1065

Problem:    Cannot use the "dll" options on MS-Windows.
Solution:   Support the options on all platforms.  Use the built-in name as
            the default, so that it's clear what Vim is looking for.

src/if_ruby.c

@@ -677,12 +677,7 @@ ruby_runtime_link_init(char *libname, int verbose)
 ruby_enabled(verbose)
     int		verbose;
 {
-#ifdef WIN3264
-    char *dll = DYNAMIC_RUBY_DLL;
-#else
-    char *dll = *p_rubydll ? (char *)p_rubydll : DYNAMIC_RUBY_DLL;
-#endif
-    return ruby_runtime_link_init(dll, verbose) == OK;
+    return ruby_runtime_link_init((char *)p_rubydll, verbose) == OK;
 }
 #endif /* defined(DYNAMIC_RUBY) || defined(PROTO) */