bash to sh for two scripts

These don't use any special bash features. They can use regular sh.

tools/install_modules.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 ##
 ## Author......: See docs/credits.txt

tools/package_bin.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 ##
 ## Author......: See docs/credits.txt