QGIS LTR version should notify about LTR releases

[kadarivan]

Feature description.
Version checking is a great feature, but LTR version should notify about LTR updates only.

[agiudiceandrea]

Hi @kadarivan, I think this is a bug and a regression.

@gioman, could you please change the tag from "Feature Request" to "Bug"?

@jef-n introduced a mechanism to properly handle the version check through an apache configuration rewrite rule based on the user-agent string sent by QGIS. See #31298 (comment) and #33494.

The QGIS user-agent string was changed to address some WMS problems thanks to @elpaso (see 8bd57ca and #32766 (comment)) since 3.10.2, from something like "Mozilla/5.0 QGIS/3.10.2-A Coruña" to something like "Mozilla/5.0 QGIS/31002".

Probably the apache configuration rewrite rule was not changed accordingly to the change in the user-agent string, then it fails to properly sent the right information about the current version for ltr and non ltr QGIS.

[jef-n]

Probably the apache configuration rewrite rule was not changed accordingly to the change in the user-agent string, then it fails to properly sent the right information about the current version for ltr and non ltr QGIS.

Fixed.

[agiudiceandrea]

Thanks @jef-n! But now it doesn't work properly for QGIS 3.10.1 and 3.10.0 versions...

[agiudiceandrea]

@jef-n 3.10.0 and 3.10.1 versions still send the old style user-agent string: "Mozilla/5.0 QGIS/3.10.0-A Coruña"
Now those versions incorrectly display "New QGIS version available: Visit https://download.qgis.org to get your copy of version 3.12.1", therefore a special rule should be added for these versions.

[agiudiceandrea]

Thank you again! Now it works correctly also for 3.10.0 and 3.10.1.