Correct a typo in CMakeLists.txt
Correct a typo in CMakeLists.txt

otris/ews-cpp,bkircher/ews-cpp,m-Schlitzer/ews-cpp,bkircher/ews-cpp,m-Schlitzer/ews-cpp,otris/ews-cpp,m-Schlitzer/ews-cpp,otris/ews-cpp,bkircher/ews-cpp,otris/ews-cpp