LAVA: Retry if fail to get jobs

Proxy error would occasionally happen when waiting for LAVA jobs.
Retry max to 3 times to avoid blocking CI.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I36c4707a6971d4528fe7357aa893c9b886d2a574
diff --git a/lava_helper/lava_wait_jobs.py b/lava_helper/lava_wait_jobs.py
index b1937e6..332e20c 100755
--- a/lava_helper/lava_wait_jobs.py
+++ b/lava_helper/lava_wait_jobs.py
@@ -228,7 +228,16 @@
 def main(user_args):
     """ Main logic """
     user_args.lava_rpc = "RPC2"
-    wait_for_jobs(user_args)
+    for try_time in range(3):
+        try:
+            wait_for_jobs(user_args)
+            break
+        except Exception as e:
+            print(e)
+            if try_time < 2:
+                print("Try to get LAVA jobs again...")
+            else:
+                raise e
 
 def get_cmd_args():
     """ Parse command line arguments """