Do not allow 1 GB RAM

[novoselt]

It is pretty much a bug when "simple things just don't work" with a paid plan. What is offered should "most likely work".

Since we started getting messages about 1 GB licenses not working, I think we should prohibit in the user interface buying them - probably some recent software upgrade made it more likely to cross the line in basic projects. My preference would be to set 4 GB as the minimum, not just the default, since 2 GB also was too small in a number of cases and not all problems get reported.