Fix CI executable name

Author: Niam5

.github/workflows/build.yml

@@ -100,7 +100,7 @@ jobs:
     - name: Check executables
       run: |
         cd bin/check_install/bin
-        ./authserver --version
+        ./bnetserver --version
         ./worldserver --version
 
 # Cata preservation project has been abandoned, so no need for further build checks on this project