bootstrap: Use strict behaviour

Change-Id: I3fc6819ce7c1dfc63ea1f14e4f23097b48b8a115
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/bootstrap.sh b/bootstrap.sh
index 5a6c34d..eb8056f 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -eu
+
 AUTOCONF_FILES="Makefile.in aclocal.m4 ar-lib autom4te.cache compile \
         config.guess config.h.in config.sub configure depcomp install-sh \
         ltmain.sh missing *libtool test-driver"