xserver-xorg: Add mesa-dri to depends instead of virtual/libgl
Fixes the compile problems e.g.
| checking for GL... yes
| checking for DRIPROTO... yes
| checking for DRI... no
| configure: error: Package requirements (glproto >= 1.4.14 dri >=
7.8.0) were not met:
|
| No package 'dri' found
|
| Consider adjusting the PKG_CONFIG_PATH environment variable if you
| installed software in a non-standard prefix.
