stop listing Leia compatible skins in the Matrix repo (xbmc#1594)

Co-authored-by: ronie <ronie@kodi.tv>

Author: ronie

targets.cfg

@@ -79,7 +79,7 @@ minversions =
 [matrix]
 branches = gotham,helix,isengard,jarvis,krypton,leia,matrix
 minversions =
- xbmc.gui:5.14.0,
+ xbmc.gui:5.15.0,
  xbmc.python:3.0.0,
  xbmc.json:6.0.0,
  xbmc.metadata:1.0,