Remove misplaced and duplicate dependency from pom

The dependency declaration for net.glxn:qrgen:1.3 added in commit
4358268d88049933fecb80ac3f91b0ff5f71d488 was placed outside the
<dependencies> element, resulting in pom validation errors and breaking
the build. This commit removes the offending <dependency> element, as it
is a duplicate of the original declaration added to the pom months ago
in commit 328ecf34fe825d0ad1174469b42d12e46769ba9c.