tools: Add missing keyword encapsulation in frr-reload

Fix the error below:

```
Failed to execute segment-routing  srv6   no source-address 1::1  exit exit
"segment-routing --  srv6 --   no source-address 1::1 --  exit -- exit" we failed to remove this command
% Unknown command:   no source-address 1::1

[79975|mgmtd] sending configuration
line 3: % Unknown command[76]:   source-address fc00:0:1::1
[79975|mgmtd] Configuration file[/etc/frr/frr.conf] processing failure: 2
```

Signed-off-by: Carmine Scarpitta <[email protected]>

tools/frr-reload.py

@@ -279,7 +279,7 @@ def get_normalized_interface_vrf(line):
             "policy ": {"candidate-path ": {}},
             "pcep": {"pcc": {}, "pce ": {}, "pce-config ": {}},
         },
-        "srv6": {"locators": {"locator ": {}}},
+        "srv6": {"locators": {"locator ": {}}, "encapsulation": {}},
     },
     "nexthop-group ": {},
     "route-map ": {},