fix: neg-latency quotes typo on waitAfterDelete

fixes: #2981

Author: dlapcevic

clusterloader2/testing/neg/config.yaml

@@ -2,7 +2,7 @@
 {{$smallBackendLbServiceCount := DefaultParam .CL2_SMALL_BACKEND_LB_SERVICE_COUNT 5}}
 {{$mediumBackendLbServiceCount := DefaultParam .CL2_MEDIUM_BACKEND_LB_SERVICE_COUNT 3}}
 {{$largeBackendLbServiceCount := DefaultParam .CL2_LARGE_BACKEND_LB_SERVICE_COUNT 1}}
-{{$waitAfterDeletion := DefaultParam .CL2_WAIT_AFTER_DELETION “15m”}}
+{{$waitAfterDeletion := DefaultParam .CL2_WAIT_AFTER_DELETION "15m"}}
 
 # Test
 name: neg-latency