Correct WSL build instructions
Correct WSL build instructions

The builds instructions were outdated and faulty. This fix should make
the difference clearer between cross compiling and using WSL.

gridcoin/Gridcoin-Research,caraka/gridcoinresearch,Git-Jiro/Gridcoin-Research,caraka/gridcoinresearch,Git-Jiro/Gridcoin-Research,gridcoin/Gridcoin-Research,caraka/gridcoinresearch,theMarix/Gridcoin-Research,theMarix/Gridcoin-Research,caraka/gridcoinresearch,theMarix/Gridcoin-Research,gridcoin/Gridcoin-Research,gridcoin/Gridcoin-Research,tomasbrod/Gridcoin-Research,Git-Jiro/Gridcoin-Research,Git-Jiro/Gridcoin-Research,TheCharlatan/Gridcoin-Research,caraka/gridcoinresearch,tomasbrod/Gridcoin-Research,gridcoin/Gridcoin-Research,caraka/gridcoinresearch,TheCharlatan/Gridcoin-Research,tomasbrod/Gridcoin-Research,TheCharlatan/Gridcoin-Research,theMarix/Gridcoin-Research,gridcoin/Gridcoin-Research,tomasbrod/Gridcoin-Research,theMarix/Gridcoin-Research,Git-Jiro/Gridcoin-Research,tomasbrod/Gridcoin-Research,TheCharlatan/Gridcoin-Research,theMarix/Gridcoin-Research,TheCharlatan/Gridcoin-Research