优化：构建镜像使用阿里云yum源，加速构建

Dockerfile

@@ -2,7 +2,11 @@ FROM centos:centos7.6.1810
 MAINTAINER chenjh "842761733@qq.com"
 ADD jodconverter-web/target/kkFileView-*.tar.gz /opt/
 COPY fonts/* /usr/share/fonts/chienes/
-RUN yum install -y kde-l10n-Chinese &&\
+RUN mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup &&\
+    curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo &&\
+    sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo &&\
+    yum makecache &&\
+    yum install -y kde-l10n-Chinese &&\
     yum install -y glibc-common &&\
     yum install -y fontconfig &&\
     yum install -y mkfontscale &&\