Fix driving logic (off-by-one)

ledbanner-driver.ino

@@ -335,7 +335,7 @@ void writeBuffer(byte* buff) {
   if(micros() - previousSet > 500 ) { // 1500
     clear();
 
-    if(column > 15) column = 0;
+    if(column > 14) column = 0;
 
     int actualColumn = column % 3 * 5 + column / 3;