Fix typo: 'default default' -> 'default' in README

Signed-off-by: RoomWithOutRoof <roomwithoutroof@outlook.com>

Author: RoomWithOutRoof

README.md

@@ -59,7 +59,7 @@ mkdir build
 cd build
 cmake -G "Visual Studio 15" ..
 ```
-The default default will build for x86. For 64-bit run:
+The default will build for x86. For 64-bit run:
 
 ```cmd
 cmake -G "Visual Studio 15 Win64" ..