Update dashboard.py

Potential fix for #762

src/dashboard.py

@@ -3115,9 +3115,12 @@ def peerInformationBackgroundThread():
     time.sleep(10)
     while True:
         with app.app_context():
-            for c in WireguardConfigurations.values():
-                if c.getStatus():
             try:
+                curKeys = list(WireguardConfigurations.keys())
+                for name in curKeys:
+                    if name in WireguardConfigurations.keys() and WireguardConfigurations.get(name) is not None:
+                        c = WireguardConfigurations.get(name)
+                        if c.getStatus():
                             c.getPeersTransfer()
                             c.getPeersLatestHandshake()
                             c.getPeersEndpoint()