doh: 2 numbers are less than 3..

git-svn-id: https://xpra.org/svn/Xpra/trunk@13236 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/xpra/client/gl/gl_check.py

@@ -222,7 +222,7 @@ def redirect_log(logger_name):
                 _version_warning_shown = True
         vsplit = pyopengl_version.split('.')
         #we now require PyOpenGL 3.1 or later
-        if vsplit[:2]<['3','0','1'] and not force_enable:
+        if vsplit[:3]<['3','0','1'] and not force_enable:
             gl_check_error("PyOpenGL version %s is too old and buggy" % pyopengl_version)
             return {}
         if vsplit[:2]<['3','1']: