On NetBSD don't use setruid() and setrgid().

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@7158 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

process.c

@@ -94,6 +94,11 @@ static VALUE S_Tms;
 #define HAVE_44BSD_SETGID 1
 #endif
 
+#ifdef __NetBSD__
+#undef HAVE_SETRUID
+#undef HAVE_SETRGID
+#endif
+
 #if defined(__MacOS_X__) || defined(__bsdi__)
 #define BROKEN_SETREUID 1
 #define BROKEN_SETREGID 1