Fix Mint block propagation towards Wildcat

[zupzup]

• On dev wildcat, it seems Mint blocks are not propagated anymore (which then leads to req to pay to fail)
• It seems like Issue and Endorse blocks are propagated (together with their bills)

[zupzup]

It doesn't make much sense to investigate this now, since Wildcat is being rebuilt heavily.

I tested it today using dev branch on Wildcat and latest E-Bill and at least the flow including req to pay worked (including block propagation).