The krb5 build process tries to install the setuid-bit program ksu such
that it is owned by root. This fails when the build executes as a normal
user, which is usually the case when building OpenWrt. This patch fixes
this. Here is the symptom:

making install in clients/ksu...
make[6]: Entering directory '.../build_dir/target-x86_64_musl/krb5-1.22/src/clients/ksu'
for f in ksu; do \
  .../staging_dir/host/bin/ginstall -c  -m 4755 -o root $f \
        .../build_dir/target-x86_64_musl/krb5-1.22/ipkg-install/usr/bin/`echo $f|sed 's&$&&;s&^&&'`; \
done
ginstall: invalid user 'root'
make[6]: [Makefile:640: install] Error 1 (ignored)

As of publication, Fedora applies a similar
patch for the same reason. Their patch, which can be
found in the repository for their krb5 package, is named
0010-downstream-Do-not-set-root-as-ksu-file-owner.patch.

--- a/src/config/pre.in
+++ b/src/config/pre.in
@@ -185,7 +185,7 @@ INSTALL_PROGRAM=@INSTALL_PROGRAM@ $(INST
 INSTALL_SCRIPT=@INSTALL_PROGRAM@
 INSTALL_DATA=@INSTALL_DATA@
 INSTALL_SHLIB=@INSTALL_SHLIB@
-INSTALL_SETUID=$(INSTALL) $(INSTALL_STRIP) -m 4755 -o root
+INSTALL_SETUID=$(INSTALL) $(INSTALL_STRIP) -m 4755
 ## This is needed because autoconf will sometimes define @exec_prefix@ to be
 ## ${prefix}.
 prefix=@prefix@