debian: preinst: don't force the default shell to bash

debian/qubes-core-agent.preinst

@@ -41,13 +41,6 @@ if [ "$1" = "install" ] ; then
     mkdir -p /lib/modules
     #mkdir -p -m 0700 /var/log/xen  # xen-utils-common should do this
 
-    # --------------------------------------------------------------------------
-    # Many Qubes scripts reference /bin/sh expecting the shell to be bash but
-    # in Debian it is dash so some scripts will fail so force an alternate for
-    # /bin/sh to be /bin/bash
-    # --------------------------------------------------------------------------
-    update-alternatives --force --install /bin/sh sh /bin/bash 999
-
     # --------------------------------------------------------------------------
     # Remove `mesg` from root/.profile?
     # --------------------------------------------------------------------------