fix: chown /var/lib/overleaf mount point to www-data

The init script chowns all subdirectories but not the mount point
itself. When the host volume is owned by a non-www-data user with
restrictive permissions (e.g. 770), the web process cannot traverse
the directory and crashes with EACCES, causing a 502.

Fixes #1325 and #1465

server-ce/init_scripts/100_make_overleaf_data_dirs.sh

@@ -2,6 +2,7 @@
 set -e
 
 mkdir -p /var/lib/overleaf/data
+chown www-data:www-data /var/lib/overleaf
 chown www-data:www-data /var/lib/overleaf/data
 
 mkdir -p /var/lib/overleaf/data/compiles