Fix some lintian errors

Fix lintian errors related to maintainer, postinst script and
permissions.

Change-Id: I6924ff92ff5453fa7e562a6188c2c91cea87df68

server/CMakeLists.txt

@@ -52,7 +52,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -msse -msse2 -std=c++11 ")
 # set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -m32")
 
 if ("${CMAKE_BUILD_TYPE}" STREQUAL Release)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -s")
 else()
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ggdb -O0 -DDEBUG")
 endif()