Fixed decoding bug that would cause incorrect messages to be output

SourceFiles/Playfair.cpp

@@ -265,10 +265,10 @@ std::string Playfair::decode(){
 			--col2;
 
 			//Wrap around
-			if(col1 > 4){
+			if(col1 < 0){
 				col1 += 5;
 			}
-			if(col2 > 4){
+			if(col2 < 0){
 				col2 += 5;
 			}
 		}
@@ -278,10 +278,10 @@ std::string Playfair::decode(){
 			--row2;
 
 			//Wrap around
-			if(row1 > 4){
+			if(row1 < 0){
 				row1 += 5;
 			}
-			if(row2 > 4){
+			if(row2 < 0){
 				row2 += 4;
 			}
 		}