Fix typo in test

Signed-off-by: d-dashkov <[email protected]>

Author: d-dashkov

tests/static_routes_test.py

@@ -26,7 +26,7 @@
 Error: ip address is not valid.
 '''
 ERROR_INVALID_PORTCHANNEL = '''
-Error: portchannel doest not exist.
+Error: portchannel does not exist.
 '''