API adds right Y for svggraph widget even when there are no items assigned to the right Y.
Turns out - it's a default behavior for SVG Graph. But Classic graphs widget and graph prototype widget, uses different defaults - no Y axis

Steps to reproduce: 

1. Add a template widget svggraph without specifying righty field.

Result:

Expected:
Similar behavior for all graph types! Its quite strange to see right Y when there are no data assigned