suites: gprs: Keep terminating all iperf3 processes if one fails to terminate

Change-Id: I0cc183529988463800e0d40c8cf3a4cea041031c
diff --git a/suites/gprs/lib/testlib.py b/suites/gprs/lib/testlib.py
index ac3a847..284ca63 100644
--- a/suites/gprs/lib/testlib.py
+++ b/suites/gprs/lib/testlib.py
@@ -26,7 +26,10 @@
             proc.wait()
     except Exception as e:
         for proc in procs:
-            proc.terminate()
+            try:
+                proc.terminate()
+            except Exception:
+                print("Exception while terminating process %r" % repr(process))
         raise e