fix #1055 for net-ilb-l7

tests/modules/net_ilb_l7/fixture/test.negs.tfvars

@@ -9,11 +9,13 @@ neg_configs = {
   custom = {
     gce = {
       zone = "europe-west1-b"
-      endpoints = [{
-        ip_address = "10.0.0.10"
-        instance   = "test-1"
-        port       = 80
-      }]
+      endpoints = {
+        e-0 = {
+          ip_address = "10.0.0.10"
+          instance   = "test-1"
+          port       = 80
+        }
+      }
     }
   }
 }