[oData Handler] Empty response e.g. when updating an entity leads to an error

[chrisweirich]

A response from an odata service without content seems to be normal for some types of requests (update, delete, ...). But the handler throws an error in case of "update" - maybe on more occasions.

Suggestion
https://github.com/Urigo/graphql-mesh/blob/master/packages/handlers/odata/src/index.ts#L1505

// Accept empty response
if (responseText === '') return;

return handleResponseText(responseText, urlString, info);