Import function does not work with existing GPS .svg

As reported by a customer, the GPS Data Blocks .svg download on [this learn page](http://learn.parallax.com/support/reference/propeller-blocklyprop-block-reference/sensor/gps/gps-wiring-example-code) shows up as *valid* but the Replace and Append buttons do nothing.

A concern is that we experienced this import behavior once before, then fixed it; has old code been merged again?