Correct bug with reporting macOS version

gprMax/utilities/host_info.py

@@ -126,7 +126,7 @@ def get_host_info():
             hyperthreading = False
 
         # OS version
-        if int(platform.mac_ver()[0].split('.')[1]) < 12:
+        if float(platform.mac_ver()[0]) < 12:
             osversion = 'Mac OS X (' + platform.mac_ver()[0] + ')'
         else:
             osversion = 'macOS (' + platform.mac_ver()[0] + ')'