Harden autostart logic for non-existent airframe values

This ensures that the user is pushed back to the airframe configuration stage.

Tools/px4airframes/rcout.py

@@ -78,6 +78,8 @@ class RCOutput():
             result += "else\n"
             result += "\techo \"ERROR  [init] No file matches SYS_AUTOSTART value found in : /etc/init.d/airframes\"\n"
             result += "\techo \"ERROR  [init] No file matches SYS_AUTOSTART value found in : /etc/init.d/airframes\" >> $LOG_FILE\n"
+            # Reset the configuration
+            result += "\tparam set SYS_AUTOSTART 0\n"
             result += "\ttone_alarm ${TUNE_ERR}\n"
         result += "fi\n"
         result += "unset AIRFRAME"