glfwGetTime work fine in lib but return 0 in dll

Apologies my first paragraph is misleading, and should have added more information.

The correct solution is the final paragraph:

The simplest way around this would be to build GLFW as shared when using it with shared libraries (and define the GLFW_DLL macro from projects using it). A more complex approach would be to ensure GLFW is built with the correct import/export macros when linked into a DLL.