let miniupnp's cmakelist handle defaults

external/CMakeLists.txt

@@ -60,9 +60,6 @@ else()
     message(STATUS "Using miniupnpc from local source tree (/external/miniupnpc)")
   endif()
 
-  set(UPNPC_BUILD_STATIC ON CACHE BOOL "Build static library")
-  set(UPNPC_BUILD_SHARED OFF CACHE BOOL "Build shared library")
-  set(UPNPC_BUILD_TESTS OFF CACHE BOOL "Build test executables")
   add_subdirectory(miniupnpc)
 
   set_property(TARGET upnpc-static PROPERTY FOLDER "external")

external/miniupnpc/CMakeLists.txt

@@ -18,7 +18,7 @@ endif()
 ]]
 
 option (UPNPC_BUILD_STATIC "Build static library" TRUE)
-option (UPNPC_BUILD_SHARED "Build shared library" TRUE)
+option (UPNPC_BUILD_SHARED "Build shared library" FALSE)
 if (NOT WIN32)
   option (UPNPC_BUILD_TESTS "Build test executables" FALSE)
 endif (NOT WIN32)