Catch OS error in TLS server protocol test (#1171)

Author: jboddey

modules/test/tls/python/src/tls_util.py

@@ -158,6 +158,9 @@ def get_public_certificate(self,
     except socket.timeout:
       LOGGER.info('Socket timeout error')
       return None
+    except OSError as e:
+      LOGGER.error(e)
+      return None
 
     return cert_pem