When using gitHub flow we don't need to Fetch other branches then master

Can we have an environment configuration switch or argument to stop this error... (?)

```[UpdateAssemblyInfo] GitFlowVersionTask.UpdateAssemblyInfo
[18:06:08][GitFlowVersionTask.UpdateAssemblyInfo] Applicable build agent found: 'TeamCity'.
[18:06:08][GitFlowVersionTask.UpdateAssemblyInfo] Executing PerformPreProcessingSteps for 'TeamCity'.
[18:06:08][GitFlowVersionTask.UpdateAssemblyInfo] One remote found (origin -> 'https://sfarmar@github.com/Particular/Website.Backend.git').
[18:06:08][GitFlowVersionTask.UpdateAssemblyInfo] Fetching from remote 'origin' using the following refspecs: +refs/heads/*:refs/remotes/origin/*.
[18:06:08]
[GitFlowVersionTask.UpdateAssemblyInfo] Error occurred: LibGit2Sharp.LibGit2SharpException: An error was raised by libgit2. Category = Net (Error).
Request failed with status code: 401
   at LibGit2Sharp.Core.Ensure.HandleError(Int32 result)
   at LibGit2Sharp.Core.Proxy.git_remote_connect(RemoteSafeHandle remote, GitDirection direction)
   at LibGit2Sharp.Network.DoFetch(RemoteSafeHandle remoteHandle, FetchOptions options)
   at LibGit2Sharp.Network.Fetch(Remote remote, FetchOptions options)
   at GitFlowVersion.GitFlowVersion.GitHelper.NormalizeGitDirectory(String gitDirectory) in c:\BuildAgent\work\5e0d79a4e3943b17\GitFlowVersion\BuildServers\GitHelper.cs:line 17
   at GitFlowVersion.TeamCity.PerformPreProcessingSteps(String gitDirectory) in c:\BuildAgent\work\5e0d79a4e3943b17\GitFlowVersion\BuildServers\TeamCity.cs:line 20
   at GitFlowVersionTask.UpdateAssemblyInfo.InnerExecute() in c:\BuildAgent\work\5e0d79a4e3943b17\GitFlowVersionTask\UpdateAssemblyInfo.cs:line 85
   at GitFlowVersionTask.UpdateAssemblyInfo.Execute() in c:\BuildAgent\work\5e0d79a4e3943b17\GitFlowVersionTask\UpdateAssemblyInfo.cs:line 43```