I accidentally messed up nginx config and tried to login via Github oauth, and for some reason I'm now permanently unable to access from Chrome browser at this IP address. Clearing cache / chrome incognito also does not work.

Seems github is rejecting my logins, so issue may not be within this plugin.

Firefox, etc. other browsers work fine.

```
java.lang.RuntimeException: org.kohsuke.github.HttpException: Server returned HTTP response code: 401, message: 'Unauthorized' for URL: https://api.github.com/user
at org.jenkinsci.plugins.GithubSecurityRealm$1.authenticate(GithubSecurityRealm.java:564)
at jenkins.security.BasicHeaderRealPasswordAuthenticator.authenticate(BasicHeaderRealPasswordAuthenticator.java:56)
at jenkins.security.BasicHeaderProcessor.doFilter(BasicHeaderProcessor.java:79)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at org.acegisecurity.context.HttpSessionContextIntegrationFilter.doFilter(HttpSessionContextIntegrationFilter.java:249)
at hudson.security.HttpSessionContextIntegrationFilter2.doFilter(HttpSessionContextIntegrationFilter2.java:67)
at hudson.security.ChainedServletFilter$1.doFilter(ChainedServletFilter.java:87)
at hudson.security.ChainedServletFilter.doFilter(ChainedServletFilter.java:76)
at hudson.security.HudsonFilter.doFilter(HudsonFilter.java:171)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at org.kohsuke.stapler.compression.CompressionFilter.doFilter(CompressionFilter.java:49)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at hudson.util.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:82)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
at org.kohsuke.stapler.DiagnosticThreadNameFilter.doFilter(DiagnosticThreadNameFilter.java:30)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1652)
````