Fix flake8, black and pylint errors in code

Change-Id: Ic03f4d31e2ba9801be20d3679bd5749948cab39d
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>
diff --git a/osm_ee/util/util_grpc.py b/osm_ee/util/util_grpc.py
index 5fe8fc5..2dc68fa 100644
--- a/osm_ee/util/util_grpc.py
+++ b/osm_ee/util/util_grpc.py
@@ -14,17 +14,19 @@
 def create_secure_context() -> ssl.SSLContext:
     # retrieve certificates from secrets
     if not _retrieve_certs():
-        logger.warning("TLS Certificates not found, starting gRPC server in unsecure mode")
+        logger.warning(
+            "TLS Certificates not found, starting gRPC server in unsecure mode"
+        )
         return None
     # create SSL context
     ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
     ctx.verify_mode = ssl.CERT_REQUIRED
     ctx.load_cert_chain(SERVER_CERT_FILE, SERVER_KEY_FILE)
     ctx.load_verify_locations(CLIENT_CA_FILE)
-    ctx.set_ciphers('ECDHE+AESGCM:ECDHE+CHACHA20:DHE+AESGCM:DHE+CHACHA20')
-    ctx.set_alpn_protocols(['h2'])
+    ctx.set_ciphers("ECDHE+AESGCM:ECDHE+CHACHA20:DHE+AESGCM:DHE+CHACHA20")
+    ctx.set_alpn_protocols(["h2"])
     try:
-        ctx.set_npn_protocols(['h2'])
+        ctx.set_npn_protocols(["h2"])
     except NotImplementedError:
         pass
     return ctx