pki: T6464: sstpc interface not reloaded when updating SSL certificat…

…e(s)

The SSTPC client was not reloaded/restarted with the new SSL certificate(s)
after a change in the PKI subsystem.

This was due to missing dependencies.

(cherry picked from commit 42294cc)

data/config-mode-dependencies/vyos-1x.json

@@ -30,7 +30,8 @@
         "ipsec": ["vpn_ipsec"],
         "openconnect": ["vpn_openconnect"],
         "rpki": ["protocols_rpki"],
-        "sstp": ["vpn_sstp"]
+        "sstp": ["vpn_sstp"],
+        "sstpc": ["interfaces_sstpc"]
     },
     "vpn_ipsec": {
         "nhrp": ["protocols_nhrp"]