Fix several issues with last PRs

[mrheinen]

Ok this fixes 5 problems:

• The CMakeLists.txt file contained a typo
• The updated transactions call was using an outdated interface.
• The simplewallet did not build due to incorrect refresh calls.
• Missing return statement in net_helper
• Unused variable was removed

[mrheinen]

Attached is a build log showing that it now builds without warnings or errors.

build.log

[alebeta90]

thanks! you are solving the error i got today compiling

[haruto-tanno]

That works fine, ready for merging. Thanks