[buildbot] docker,worker: install gcc-mulitlib

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/56f05546ab38e0675586c853503a5013c39a0a32

commit 56f05546ab38e0675586c853503a5013c39a0a32
Author: Paul Spooren <mail at aparcar.org>
AuthorDate: Sun Jan 10 10:25:38 2021 -1000

    docker,worker: install gcc-mulitlib
    
    From openwrt/docker[1]:
    
    This is required for luajit, which is in packages feed.  While it works
    fine for ARMv8 (tested by using Github Actions: aarch64_cortex-a53) and
    x84_x64 (tested inside Docker container, it does not work for 32-bits
    target and because of that we need to install gcc-multilib.
    
    Luajit fails with the following output: (tested against target:
            arm_cortex-a9+vfpv3-d16_musl_eabi inside Docker SDK image)
    
    /usr/include/limits.h:26:10: fatal error: bits/libc-header-start.h: No
    such file or directory #include <bits/libc-header-start.h>
    ^~~~~~~~~~~~~~~~~~~~~~~~~~
    
    [1]: https://github.com/openwrt/docker/pull/74/commits/f9da188d53fd9809ca4911089611e1f42422d049
    
    Signed-off-by: Paul Spooren <mail at aparcar.org>
---
 docker/buildworker/Dockerfile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/docker/buildworker/Dockerfile b/docker/buildworker/Dockerfile
index 8e7960b..380ecc5 100644
--- a/docker/buildworker/Dockerfile
+++ b/docker/buildworker/Dockerfile
@@ -17,6 +17,7 @@ RUN \
 		ccache \
 		curl \
 		gawk \
+		gcc-multilib \
 		git-core \
 		gosu \
 		libncurses5-dev \