development/google-go-lang: Unset BASH_ENV during build

I have no idea why, but having BASH_ENV set (or at least,
as it is in my build environment) will cause run.bash to
exit with the same error seen here:

  http://permalink.gmane.org/gmane.comp.lang.go.devel/34316

For the sake of completeness, here's my $HOME/.profile:

  BASH_ENV=$HOME/.bashrc
  export BASH_ENV
  . $HOME/.bashrc

As part of the troubeshooting process, I commented out only
the first two lines (to confirm that it wasn't the contents
of $HOME/.bashrc causing the problem) and the build proceeds
correctly.

Signed-off-by: Robby Workman <rworkman@slackbuilds.org>

development/google-go-lang/google-go-lang.SlackBuild

@@ -82,6 +82,8 @@ export GOOS="linux"
 export GOBIN="${PKG}/usr/bin"
 export GOARCH="${GARCH}"
 
+unset BASH_ENV # Not sure why, but this causes run.bash to fail --rworkman
+
 mkdir -p "${GOBIN}"
 cd src