services: admin: Allow non-string values for setenv assoc-list entries

modules/radix/services/admin.scm

@@ -41,7 +41,7 @@
   (map (match-lambda
          ((var . #t) var)
          ((var . #f) (string-append "-" var))
-         ((var . value) (string-append var "=" value)))
+         ((var . value) (format #f "~a=~a" var value)))
        val))
 (define-maybe list-of-strings)
 (define-maybe assoc-list)