disable Extras BulletRobotics by default in cmake

Extras/BulletRobotics/CMakeLists.txt

@@ -290,7 +290,6 @@ IF (INSTALL_EXTRA_LIBS)
     SET_TARGET_PROPERTIES(BulletRobotics  PROPERTIES FRAMEWORK true)
     SET_TARGET_PROPERTIES(BulletRobotics PROPERTIES PUBLIC_HEADER "PhysicsClientC_API.h" )
   ENDIF (APPLE AND BUILD_SHARED_LIBS AND FRAMEWORK)	
-ENDIF (INSTALL_EXTRA_LIBS)
 
 IF(NOT MSVC)
     CONFIGURE_FILE(${CMAKE_CURRENT_SOURCE_DIR}/bullet_robotics.pc.cmake
@@ -301,4 +300,6 @@ IF(NOT MSVC)
       DESTINATION
       ${PKGCONFIG_INSTALL_PREFIX}
     )
-ENDIF(NOT MSVC)
+ENDIF(NOT MSVC)
+ENDIF (INSTALL_EXTRA_LIBS)
+