util/docker: change main branch back to master for encapsulate

The branch for the encapsulate tool accidentally got caught up in the
switch from master to main. The default branch for this tool has not
changed, so still needs to be referenced as master.

Change-Id: I0ff47308dcbf30888e4e88637bab63f20467307a
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79005
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
diff --git a/util/docker/coreboot-jenkins-node/Dockerfile b/util/docker/coreboot-jenkins-node/Dockerfile
index 91c8e3a..ae29e43 100644
--- a/util/docker/coreboot-jenkins-node/Dockerfile
+++ b/util/docker/coreboot-jenkins-node/Dockerfile
@@ -55,7 +55,7 @@
 	echo "tmpfs /home/coreboot/.ccache tmpfs rw,mode=1777 0 0" >> /etc/fstab
 
 # Build encapsulate tool
-ADD https://raw.githubusercontent.com/coreboot/encapsulate/main/encapsulate.c /tmp/encapsulate.c
+ADD https://raw.githubusercontent.com/coreboot/encapsulate/master/encapsulate.c /tmp/encapsulate.c
 RUN gcc -o /usr/sbin/encapsulate /tmp/encapsulate.c && \
 	chown root /usr/sbin/encapsulate && \
 	chmod +s /usr/sbin/encapsulate