deb/pack.sh: fix maintainer email

Correct the email alias used in the "Maintainer" property of the Debian
package.

Reported-by: Jeff Hostetler <jeffhostetler@github.com>
Signed-off-by: Victoria Dye <vdye@github.com>

Author: vdye

build/package/deb/pack.sh

@@ -81,7 +81,7 @@ Section: vcs
 Priority: optional
 Architecture: $ARCH
 Depends:
-Maintainer: Git Bundle Server <gitfundamentals@github.com>
+Maintainer: Git Bundle Server <git-fundamentals@github.com>
 Description: A self-hostable Git bundle server.
 EOF