Extend retry sleep after server fault

Change Ic9eed8352c64f183ca4077e141c6b94f81a9b91a introduced retry sleep
for server errors, but the 1 second sleep is not enough for some cases.

Related-Bug: #2030855
Change-Id: Ib8072397b873c7856523228efaa4ccd7911deda5
diff --git a/tempest/lib/common/utils/test_utils.py b/tempest/lib/common/utils/test_utils.py
index c79db15..7b85dec 100644
--- a/tempest/lib/common/utils/test_utils.py
+++ b/tempest/lib/common/utils/test_utils.py
@@ -93,7 +93,7 @@
             if attempt >= 3:
                 raise
             LOG.warning('Got ServerFault while running %s, retrying...', func)
-            time.sleep(1)
+            time.sleep(5)
 
 
 def call_until_true(func, duration, sleep_for, *args, **kwargs):