Speed up timeit arguments test

IPython/core/tests/test_magic.py

@@ -1165,8 +1165,8 b' def test_time_no_var_expand():'
 def test_timeit_arguments():
     "Test valid timeit arguments, should not cause SyntaxError (GH #1269)"
     if sys.version_info < (3,7):
-        _ip.magic("timeit ('#')")
+        _ip.magic("timeit -n1 -r1 ('#')")
     else:
         # 3.7 optimize no-op statement like above out, and complain there is
         # nothing in the for loop.
-        _ip.magic("timeit a=('#')")
+        _ip.magic("timeit -n1 -r1 a=('#')")