duplicate exports

[JaeseungYeom]

Line 273 and 283 if CMakeLists.txt are duplicate and causes error with FetchContent
https://github.com/hariharan-devarajan/cpp-logger/blob/8da41b6e6e334475e24a9cd474a92435681c2e95/CMakeLists.txt#L273

[JaeseungYeom]

Another issue is the use of CMAKE_BINARY_DIR instead of CMAKE_CURRENT_BINRARY_DIR