execute: drop empty assignments from env blocks on execution but keep them around otherwise to make them visible
diff --git a/src/load-fragment.c b/src/load-fragment.c
index 334dd68..261180d 100644
--- a/src/load-fragment.c
+++ b/src/load-fragment.c
@@ -1399,7 +1399,7 @@
                         goto finish;
                 }
 
-                t = strv_env_set(*env, u);
+                t = strv_append(*env, u);
                 free(u);
 
                 if (!t) {