Put last saved config at the end, so it will be uploaded last

Rather than updating config in place, remove the old config and put the new config at the end of the config section.

This means the last config the user entered will be uploaded to hardware last which is likely what they wanted (previously the order config was written was set by whatever order the user happened to first enter each of wc/wc1/wc2 config - which is rather arbitrary)
Merge remote-tracking branch 'upstream/master'
Merge pull request #5 from stoduk/master

Save the last entered config at the end of config block, so it is uploaded to MoPi last