Fix whitespace error in template

bin/mkexec

         test    => "import unittest\n\n\n"
                    . "class TestCase(unittest.TestCase):\n"
                    . "    pass\n\n\n"
-                   . "if __name__=='__main__':\n"
+                   . "if __name__ == '__main__':\n"
                    ."    unittest.main()\n",
     },
     pl => {