Checkmk Werk 11543: Wrong handling of 'None' values in bonding checks

ID: 11543 Title: Wrong handling of 'None' values in bonding checks Component: Checks & agents Level: 1 Class: Bug fix Version: 2.0.0i2 Discovery and check functions for *_bonding would are provided with "None" instead of None values but don't handle them correctly. This fix doesn't turn "None" into None but handles those values correctly