cgi-io: cmake: enable extra compiler warnings

Spotting issues during compilation is cheaper.

Signed-off-by: Petr Štetiar <ynezz@true.cz>

net/cgi-io/src/CMakeLists.txt

@@ -9,7 +9,8 @@ FIND_LIBRARY(ubox NAMES ubox)
 FIND_LIBRARY(ubus NAMES ubus)
 INCLUDE_DIRECTORIES(${ubus_include_dir})
 
-ADD_DEFINITIONS(-Os -Wall -Werror --std=gnu99 -g3 -Wmissing-declarations)
+ADD_DEFINITIONS(-Os -Wall -Werror -Wextra --std=gnu99 -g3)
+ADD_DEFINITIONS(-Wno-unused-parameter -Wmissing-declarations)
 
 SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")