forgot to clear the ansi.esc if an error occured

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@571

src/dos/dev_con.h

@@ -144,6 +144,7 @@ bool device_CON::Write(Bit8u * data,Bit16u * size) {
             case 'M':/* scrolling UP*/ 
             default:
                 LOG_DEBUG("ANSI: unknown char %c after a esc",data[count]); /*prob () */
+                ClearAnsi();
                 break;
             }
             count++;