committing changes in /etc after apt run

Package changes:
-chromium-libpdf 31.0.1612.0-1
+chromium-libpdf 31.0.1622.0-1
-downgrade 4.2-1
+downgrade 4.2.1-1
-virtualbox-ext-oracle 4.2.16-1
+virtualbox-ext-oracle 4.2.18-1