Minor cmake improvements for the emscripten build (#337)

Author: anutosh491

CMakeLists.txt

@@ -78,10 +78,8 @@ if(EMSCRIPTEN)
     add_compile_definitions(XEUS_CPP_EMSCRIPTEN_WASM_BUILD)
     message("Build with emscripten")
     set_property(GLOBAL PROPERTY TARGET_SUPPORTS_SHARED_LIBS TRUE)
-    set(XEUS_CPP_BUILD_STATIC ON)
     set(XEUS_CPP_BUILD_SHARED OFF)
     set(XEUS_CPP_BUILD_EXECUTABLE OFF)
-    set(XEUS_CPP_USE_SHARED_XEUS ON)
     set(XEUS_CPP_USE_SHARED_XEUS_CPP OFF)
     # ENV (https://github.com/emscripten-core/emscripten/commit/6d9681ad04f60b41ef6345ab06c29bbc9eeb84e0)
     set(EMSCRIPTEN_FEATURES "${EMSCRIPTEN_FEATURES} -s \"EXPORTED_RUNTIME_METHODS=[ENV']\"")