Version fix: dde-dock-5.1.0.9

[finwo]

About 8 hours ago, dde-dock 5.1.0.9 got tagged. Your history shows this happened about 9 days ago, so they've probably re-tagged the release for whatever reason.

This PR will update to the current version on https://github.com/linuxdeepin/dde-dock/releases/tag/5.1.0.9

---

Build log containing the error:

>>> Emerging (1 of 7) dde-base/dde-dock-5.1.0.9::deepin
 * Fetching files in the background.
 * To view fetch progress, run in another terminal:
 * tail -f /var/log/emerge-fetch.log
>>> Downloading 'https://github.com/linuxdeepin/dde-dock/archive/5.1.0.9.tar.gz'
--2020-05-19 17:51:59--  https://github.com/linuxdeepin/dde-dock/archive/5.1.0.9.tar.gz
Resolving github.com... 140.82.112.4
Connecting to github.com|140.82.112.4|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://codeload.github.com/linuxdeepin/dde-dock/tar.gz/5.1.0.9 [following]
--2020-05-19 17:51:59--  https://codeload.github.com/linuxdeepin/dde-dock/tar.gz/5.1.0.9
Resolving codeload.github.com... 140.82.113.10
Connecting to codeload.github.com|140.82.113.10|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: unspecified [application/x-gzip]
Saving to: ‘/var/cache/distfiles/dde-dock-5.1.0.9.tar.gz.__download__’

/var/cache/distfile     [   <=>              ] 722.32K  1.36MB/s    in 0.5s

2020-05-19 17:52:00 (1.36 MB/s) - ‘/var/cache/distfiles/dde-dock-5.1.0.9.tar.gz.__download__’ saved [739654]

!!! Fetched file: dde-dock-5.1.0.9.tar.gz VERIFY FAILED!
!!! Reason: Filesize does not match recorded size
!!! Got:      739654
!!! Expected: 736845
Refetching... File renamed to '/var/cache/distfiles/dde-dock-5.1.0.9.tar.gz._checksum_failure_.504p21c_'

!!! Couldn't download 'dde-dock-5.1.0.9.tar.gz'. Aborting.
 * Fetch failed for 'dde-base/dde-dock-5.1.0.9', Log file:
 *  '/var/tmp/portage/dde-base/dde-dock-5.1.0.9/temp/build.log'

>>> Failed to emerge dde-base/dde-dock-5.1.0.9, Log file:

>>>  '/var/tmp/portage/dde-base/dde-dock-5.1.0.9/temp/build.log'