[minor] Typo in comment

Author: BastienTr

commpy/tests/test_modulation.py

@@ -141,7 +141,7 @@ def check_BER(modem, EbN0dB, BERs_expected):
                           modem.num_bits_symbol, modem.constellation, modem.Es)
         BERs = model.link_performance(EbN0dB + 10 * log10(log2(modem.m)), 5e5, 400, 720)
         assert_allclose(BERs, BERs_expected, atol=1e-4, rtol=.1,
-                        err_msg='Wrong BER for {}-PSK modulation'.format(modem.m))
+                        err_msg='Wrong BER for a standard modulation with {} symbols'.format(modem.m))
 
     def do_qam(self, modem):
         EbN0dB = arange(8, 25, 4)