修复持续集成编译失败问题

.github/workflows/ccpp.yml

@@ -14,7 +14,7 @@ jobs:
       run: git submodule update --init
 
     - name: apt-get安装依赖库(非必选)
-      run: sudo apt-get install -y cmake  libssl-dev libmp4v2-dev libsdl-dev libavcodec-dev libavutil-dev
+      run: sudo apt-get update && sudo apt-get install -y cmake  libssl-dev libmp4v2-dev libsdl-dev libavcodec-dev libavutil-dev
 
     - name: 编译
       run: mkdir -p linux_build && cd linux_build && cmake .. && make -j4