Double brackets

src/freedombone-app-matrix

@@ -325,7 +325,7 @@ function install_matrix {
     function_check matrix_generate
     matrix_generate
 
-    if [ -z ${MATRIX_DATA_DIR}/homeserver.yaml ]; then
+    if [[ -z ${MATRIX_DATA_DIR}/homeserver.yaml ]]; then
         echo $'homeserver.yaml is zero size'
         exit 783724
     fi