fix: dev: [compose-core] minor improvement against unintended option to ``echo`` !minor

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

bin/compose-core

@@ -2845,9 +2845,9 @@ get_relation_data_file() {
     fi
 
     if [ "$new" ]; then
-        echo "$relation_config" > "$relation_data_file"
+        e "$relation_config" > "$relation_data_file"
         chmod go-rwx "$relation_data_file"  ## protecting this file
-        echo "$relation_config" | md5_compat > "$relation_data_file.md5_ref"
+        e "$relation_config" | md5_compat > "$relation_data_file.md5_ref"
     fi
     echo "$relation_data_file"
 }