Add sha

Author: IsabelParedes

recipes/recipes_emscripten/m4/recipe.yaml

@@ -8,7 +8,7 @@ package:
 
 source:
   url: https://ftp.gnu.org/gnu/m4/m4-${{ version }}.tar.gz
-  sha256:
+  sha256: 3be4a26d825ffdfda52a56fc43246456989a3630093cced3fbddf4771ee58a70
   patches:
   - patches/obstack_alloc_fail.patch