REFACTOR [a vs an]

From /dev/humancontroller.

code/botlib/be_ai_char.c

@@ -713,7 +713,7 @@ int Characteristic_Integer(int character, int index)
 	} //end else if
 	else
 	{
-		botimport.Print(PRT_ERROR, "characteristic %d is not a integer\n", index);
+		botimport.Print(PRT_ERROR, "characteristic %d is not an integer\n", index);
 		return 0;
 	} //end else if
 //	return 0;