Changed where the cached system identity expiry exception is thrown

src/Tgstation.Server.Host/Security/AuthenticationContextFactory.cs

@@ -65,11 +65,7 @@ namespace Tgstation.Server.Host.Security
 
 			ISystemIdentity systemIdentity;
 			if (user.SystemIdentifier != null)
-			{
 				systemIdentity = identityCache.LoadCachedIdentity(user);
-				if (systemIdentity == null)
-					throw new InvalidOperationException("Cached system identity has expired!");
-			}
 			else
 			{
 				if (user.LastPasswordUpdate.HasValue && user.LastPasswordUpdate < validAfter)

src/Tgstation.Server.Host/Security/IdentityCache.cs

@@ -70,11 +70,9 @@ namespace Tgstation.Server.Host.Security
 			if (user == null)
 				throw new ArgumentNullException(nameof(user));
 			lock (cachedIdentities)
-			{
 				if (cachedIdentities.TryGetValue(user.Id, out var identity))
 					return identity.SystemIdentity;
-				return null;
-			}
+			throw new InvalidOperationException("Cached system identity has expired!");
 		}
 	}
 }