Add GVM_DIR to selfupdate.
Add GVM_DIR to selfupdate.

sdkman/sdkman-cli,nobeans/gvm-cli,DealerDotCom/gvm-cli,GsusRecovery/sdkman-cli,skpal/sdkman-cli,dsyer/gvm,dsyer/gvm,shanman190/sdkman-cli,nobeans/gvm-cli,skpal/sdkman-cli,busches/gvm-cli,gvmtool/gvm-cli,jbovet/gvm,GsusRecovery/sdkman-cli,DealerDotCom/gvm-cli