fstab-generator: add newline before we start a new unit file section

We already did this for the [Mount] section, let's do the same for [Automount].

src/fstab-generator/fstab-generator.c

@@ -379,6 +379,7 @@ static int add_mount(
                 }
 
                 fprintf(f,
+                        "\n"
                         "[Automount]\n"
                         "Where=%s\n",
                         where);