Log Message:
gallery-dl: Update to 1.10.6

Changes:
1.10.6
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# Additions
 - `--exec` command-line option to specify a command to run after each
   file download (#421)

# Changes
 - Include titles in `gfycat` default filenames (#434)

# Fixes
 - Fetch working download URLs for `deviantart` (#436)
 - Various fixes and improvements for `yaplog` blogs (#443)
 - Fix image URL generation for `hitomi` galleries
 - Miscellaneous fixes for `behance` and `xvideos`