Prevent skipping in gems installation

[v-natalia]

In this step:
Installing some gems many students see the text ' If you are in China' and as they are not there, they skip the whole thing.
I suggest that we put a similar title, saying ' and If you are not in China, follow this step'

Also, I suggest that the text below 'x If you encounter the following error:' could be a clickable detail, so we avoid people removing the gems just after installing them.