[tests] set XDG_CONFIG_HOME too

test/test_config.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env bash
 
 export HOME="./test-config"
+export XDG_CONFIG_HOME="./test-config/.config"
 rm -rf ./test-config
 mkdir -p $HOME/.config
 

test/test_meta.sh

@@ -3,6 +3,7 @@
 lnav_test="${top_builddir}/src/lnav-test"
 
 export HOME="./meta-sessions"
+export XDG_CONFIG_HOME="./meta-sessions/.config"
 rm -rf "./meta-sessions"
 mkdir -p $HOME/.config