apps/grgsm_trx: fix antenna selection options
Both '--rx-antenna' and '--tx-antenna' require an argument.
diff --git a/apps/grgsm_trx b/apps/grgsm_trx
index 670d919..507ed87 100755
--- a/apps/grgsm_trx
+++ b/apps/grgsm_trx
@@ -116,7 +116,7 @@
"i:p:a:s:g:G:h",
["help", "remote-addr=", "base-port=", "device-args=",
"sample-rate=", "rx-gain=", "tx-gain=", "ppm=",
- "rx-antenna", "tx-antenna"])
+ "rx-antenna=", "tx-antenna="])
except getopt.GetoptError as err:
# Print(help and exit)
self.print_help()