Update SpectrumAnalyzer.cpp

Use this if u want :)
F5 straddles two columns, so I can see you wanting to move this, but I disagree with doing so. When I was setting up my columns, I drew boxes over the diagram and included any key whose left side was inside the box. This departs from that methodology and causes the placement of F5-F8 to be inconsistent with that of the other keys, based on the method I used.