Clear yum metadata in x32 docker

Your Name · native-api · commit 45f0d791e0fa · 2018-11-25T07:46:55.000+03:00
Fixes ccache not found in yum
[skip ci]
diff --git a/docker/Dockerfile_i686 b/docker/Dockerfile_i686
@@ -84,4 +84,6 @@ RUN curl -O https://raw.githubusercontent.com/torvalds/linux/v4.14/include/uapi/
 	curl -O https://raw.githubusercontent.com/torvalds/linux/v4.14/include/linux/compiler.h && \
 	mv videodev2.h v4l2-common.h v4l2-controls.h compiler.h /usr/include/linux
 
-ENV PATH "$HOME/bin:$PATH"
+RUN yum clean all
+
+ENV PATH "$HOME/bin:$PATH"
