Turned on Blue Tx LED for SSTV bash call

rpitx.py

@@ -51,6 +51,7 @@ if __name__ == "__main__":
     		time.sleep(5)
         elif (('s' == sys.argv[1]) or ('sstv' in sys.argv[1])):
             print("SSTV")
+	    GPIO.output(txLed, txLedOn);
 	    os.system("(while true; do (sleep 5 && cat /home/pi/CubeSatSim/wav/sstv.wav); done) | csdr convert_i16_f | csdr gain_ff 7000 | csdr convert_f_samplerf 20833 | sudo rpitx -i- -m RF -f 434.9e3")
 #	    while True:
 #		GPIO.output(txLed, txLedOff);