cosmetic: cmdline arg doc tweaks, comment

Change-Id: I60dc059879dfe15cd3415ce1ed068ded28ff084e
diff --git a/osmopy/osmo_interact_vty.py b/osmopy/osmo_interact_vty.py
index c484932..b57cd8c 100755
--- a/osmopy/osmo_interact_vty.py
+++ b/osmopy/osmo_interact_vty.py
@@ -142,6 +142,7 @@
 
         received_lines = self._command(command_str, timeout)
 
+        # send escape to cancel the '?' command line
         if command_str[-1] == '?':
             self._command('\x03', timeout)