Return failed dependency when random GitHub API exceptions occur

docs/API.dox

@@ -62,6 +62,7 @@ TGS will only every return the response codes listed here
 - 409: Conflict. Documented in the requests that use them
 - 410: Gone. Attempted to access/modify a resource that ideally should have been ready, but isn't or no longer is
 - 422: Unprocessable Entity: Used specifically when an operation that requires a server restart is unable to be performed due to the @ref Tgstation.Server.Host.Watchdog not being present in the deployment. Blame MSO. Response body contains an @ref Tgstation.Server.Api.Models.ErrorMessage
+- 424: Failed Dependency: When a request that depends on the GitHub API fails for a reason other than rate limiting. Check server logs, usually this indicates a bad access token.
 - 426: Upgrade required: Used when the client's API version is not compatible with the server's. Response body contains an @ref Tgstation.Server.Api.Models.ErrorMessage
 - 429: Rate limited. Used with operations that rely on GitHub.com. If a rate limit is hit for an operation this will be returned. Response will contain a Retry-After header
 - 500: Server error. Please report the request and response body to the code repository

src/Tgstation.Server.Host/Controllers/AdministrationController.cs

@@ -30,6 +30,8 @@ namespace Tgstation.Server.Host.Controllers
 	{
 		const string RestartNotSupportedException = "This deployment of tgstation-server is lacking the Tgstation.Server.Host.Watchdog component. Restarts and version changes cannot be completed!";
 
+		const string OctokitException = "Bad GitHub API response, check configuration! Exception: {0}";
+
 		/// <summary>
 		/// The <see cref="IGitHubClientFactory"/> for the <see cref="AdministrationController"/>
 		/// </summary>
@@ -128,6 +130,11 @@ namespace Tgstation.Server.Host.Controllers
 			{
 				return RateLimit(e);
 			}
+			catch (ApiException e)
+			{
+				Logger.LogWarning(OctokitException, e);
+				return StatusCode((int)HttpStatusCode.FailedDependency);
+			}
 		}
 
 		/// <inheritdoc />
@@ -154,6 +161,11 @@ namespace Tgstation.Server.Host.Controllers
 			{
 				return RateLimit(e);
 			}
+			catch (ApiException e)
+			{
+				Logger.LogWarning(OctokitException, e);
+				return StatusCode((int)HttpStatusCode.FailedDependency);
+			}
 
 			Logger.LogTrace("Release query complete!");
 			foreach (var release in releases)