vlgothic-ttf: update to 20200720.

pkgsrc changes:
- Specify OSDN page for HOMEPAGE

Upstream changes (roughly translated from Changelog):

* 2020/07/20
- Fix VL-PGothic/VL-Gothic symbol glyphs
  - Fix wrong L/R directions of U+23F4/U+23F5
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=860157
  - Update glyphs of U+1F643,U+1F43F per current Unicode definitions
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=823285
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=888411
  - Make several Latin1 symbols half width (VL Gothic)
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=776436
  - Update U+2FB2, U+2BF3
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=900878
  - add/fix some Greek Letter
    - add Greek Capital Letter Yot (U+037F)
    - fix Greek Small Letter Digamma (U+03dd)
    - https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=849857

* 2020/07/19
- Update M+1C,1M part of VL-PGothic/VL-Gothic to TESTFLIGHT-063a
- Update one Kanji chalacter glyph (U+9304) of VL-PGothic/VL-Gothic
    and add a ligature of era "Reiwa" (U+32FF)

(tsutsui)