vty tests: more attempts to resolve sporadic 'Broken Pipe' error

Change-Id: I3d833ddf8c62845fe68d1e5503332541a4a04a2d
diff --git a/openbsc/tests/vty_test_runner.py b/openbsc/tests/vty_test_runner.py
index 7b25d10..3fbe20d 100644
--- a/openbsc/tests/vty_test_runner.py
+++ b/openbsc/tests/vty_test_runner.py
@@ -1267,10 +1267,12 @@
                 break
             except:
                 print "\tfailed sending IPA identity at", time.strftime("%T")
+                print "\tself.proc.poll(): ", repr(self.proc.poll())
                 if retries < 1:
                     print "\tgiving up"
                     raise
-                print "\tretrying (%d attempts left)" % retries
+                print "\tretrying in a second (%d attempts left)" % retries
+                time.sleep(1)
                 retries -= 1
     else:
         if (verbose):