fix bug

src/main/java/org/cryptomator/common/mount/Mounter.java

@@ -81,7 +81,6 @@ public class Mounter {
 			var canMountToDriveLetter = service.hasCapability(MOUNT_AS_DRIVE_LETTER);
 			var canMountToParent = service.hasCapability(MOUNT_WITHIN_EXISTING_PARENT);
 			var canMountToDir = service.hasCapability(MOUNT_TO_EXISTING_DIR);
-			var mpIsDriveLetter = userChosenMountPoint.toString().matches("[A-Z]:\\\\");
 
 			if (userChosenMountPoint == null) {
 				if (service.hasCapability(MOUNT_TO_SYSTEM_CHOSEN_PATH)) {
@@ -97,6 +96,7 @@ public class Mounter {
 					builder.setMountpoint(mountPoint);
 				}
 			} else {
+				var mpIsDriveLetter = userChosenMountPoint.toString().matches("[A-Z]:\\\\");
 				if (!mpIsDriveLetter && canMountToParent && !canMountToDir) {
 					MountWithinParentUtil.prepareParentNoMountPoint(userChosenMountPoint);
 					cleanup = () -> {