build: Remove WINVER pre define in Makefile.leveldb.inlcude

Author: ken2812221

src/Makefile.leveldb.include

@@ -24,7 +24,7 @@ LEVELDB_CPPFLAGS_INT += -DLEVELDB_ATOMIC_PRESENT
 LEVELDB_CPPFLAGS_INT += -D__STDC_LIMIT_MACROS
 
 if TARGET_WINDOWS
-LEVELDB_CPPFLAGS_INT += -DLEVELDB_PLATFORM_WINDOWS -DWINVER=0x0500 -D__USE_MINGW_ANSI_STDIO=1
+LEVELDB_CPPFLAGS_INT += -DLEVELDB_PLATFORM_WINDOWS -D__USE_MINGW_ANSI_STDIO=1
 else
 LEVELDB_CPPFLAGS_INT += -DLEVELDB_PLATFORM_POSIX
 endif