Remove now-unused function mapclass::RGB()

This function was only used in assigments to mapclass::towercol. But
that variable is unused, and has been removed, so after removing that
variable, this one is unused, too.

desktop_version/src/Map.cpp

@@ -123,11 +123,6 @@ const int mapclass::areamap[] = {
 	2,2,2,2,2,0,0,2,0,3,0,0,0,0,0,0,0,0,0,0,
 };
 
-int mapclass::RGB(int red,int green,int blue)
-{
-	return (blue | (green << 8) | (red << 16));
-}
-
 int mapclass::intpol(int a, int b, float c)
 {
 	return static_cast<int>(a + ((b - a) * c));

desktop_version/src/Map.h

@@ -22,8 +22,6 @@ class mapclass
 public:
     mapclass();
 
-    int RGB(int red,int green,int blue);
-
     int intpol(int a, int b, float c);
 
     void setteleporter(int x, int y);