Fix some issues reported by lintian

Fix some issues reported by lintian

• Use secure URI in Homepage field. (homepage-field-uses-insecure-uri)
• Bump debhelper from old 12 to 13. (package-uses-old-debhelper-compat-version)

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Build and test logs for this branch can be found at https://janitor.debian.net/lintian-fixes/pkg/glw/36b09851-56af-46c3-b19e-e0b38b3df0c0.

Debdiff

These changes affect the binary packages:

[The following lists of changes regard files as different if they have different names, permissions or owners.]

Files in second set of .debs but not in first

-rw-r--r--  root/root   /usr/lib/debug/.build-id/db/2e1202ec18dde37112b2c2638b843797e56269.debug

Files in first set of .debs but not in second

-rw-r--r--  root/root   /usr/lib/debug/.build-id/34/1a0493baa0b1cc9192ee804e5d3e452a6cca41.debug

Control files of package libglw1-mesa: lines which differ (wdiff format)

• Homepage: [-http​://mesa3d.sourceforge.net/-] {+https​://mesa3d.sourceforge.net/+}

Control files of package libglw1-mesa-dbgsym: lines which differ (wdiff format)

• Build-Ids: 341a0493baa0b1cc9192ee804e5d3e452a6cca41 db2e1202ec18dde37112b2c2638b843797e56269

Control files of package libglw1-mesa-dev: lines which differ (wdiff format)

• Homepage: [-http​://mesa3d.sourceforge.net/-] {+https​://mesa3d.sourceforge.net/+}

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