MinGW: Enable -Werror by default

CMakeOptions.txt

@@ -49,12 +49,7 @@ option(BUILD_sharkd        "Build sharkd" ON)
 option(BUILD_mmdbresolve   "Build MaxMind DB resolver" ON)
 option(BUILD_fuzzshark     "Build fuzzshark" OFF)
 
-if (USE_MSYSTEM)
-	# XXX Doesn't build cleanly yet with GCC.
-	option(ENABLE_WERROR     "Treat warnings as errors" OFF)
-else()
-	option(ENABLE_WERROR     "Treat warnings as errors" ON)
-endif()
+option(ENABLE_WERROR     "Treat warnings as errors" ON)
 # Debugging is enabled for "Debug" and "RelWithDebInfo" build types.
 option(ENABLE_DEBUG      "Enable debugging for all build configurations" OFF)
 # UTF-8 debugging is enabled for "Debug" and "RelWithDebInfo" build types.