fix(connections): Guard against missing propert...
fix(connections): Guard against missing propert...

...ies definitions appearing in configured properties

For Salesforce OAuth dance sets the `instanceUrl` property which was not
declared in connector `properties` but was encountered in
`configuredProperties`.

Fixes #763

kahboom/ipaas-client,kahboom/ipaas-client,kahboom/ipaas-client,kahboom/ipaas-client