Fix crash when version_history.json is empty (#9871)

patches/server/Add-version-history-to-version-command.patch

@@ -116,6 +116,14 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +                return;
 +            }
 +
++            if (currentData == null) {
++                // Empty file
++                currentData = new VersionData();
++                currentData.setCurrentVersion(version);
++                writeFile(path);
++                return;
++            }
++
 +            if (!version.equals(currentData.getCurrentVersion())) {
 +                // The version appears to have changed
 +                currentData.setOldVersion(currentData.getCurrentVersion());