A new setting, "allowVersionCheck" has been added to the QGIS configuration ini file. If set to true (the default), users may control whether the version check is enabled or disabled through the QGIS settings dialog. When this setting is set to false, no version checking will be performed AND users will NOT have an option to enable this check in the settings dialog.
This setting is intended for use in enterprise installs where QGIS version management is handled centrally.