Drop the getKeyColor function from the header

It has no implementation, so lets not pretend we have it.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>

src/Kaleidoscope-Hardware-Model01.h

@@ -17,7 +17,6 @@ class Model01 {
   void setCrgbAt(byte row, byte col, cRGB color);
   void setCrgbAt(uint8_t i, cRGB crgb);
   cRGB getCrgbAt(uint8_t i);
-  cRGB getKeyColor(byte row, byte col);
   uint8_t getLedIndex(byte row, byte col);
 
   void scanMatrix(void);