Bug#897970: gnucash: new upstream version (3.1)

[Heinz Repp]

package: gnucash
package: gnucash-common
package: python3-gnucash
version: 3.0-1
severity: wishlist
tags: upstream

This new release fixes a couple of critical bugs that arose from the
switch to gtk3. Please consider uploading!

Thank you

Heinz Repp