Update copyright

Missed out a part in https://github.com/tenacityteam/tenacity/pull/698.

Signed-off-by: TheEvilSkeleton <theevilskeleton@riseup.net>
Reference-to: https://github.com/tenacityteam/tenacity/pull/700

src/AboutDialog.cpp

@@ -1009,7 +1009,7 @@ void AboutDialog::GeneratePreforkWebsiteInfo(wxTextOutputStream& tos) {
         .Format(
             Verbatim("<b>%s</b>").Format(ProgramName),
             wxT("&copy;"),
-            wxT("2021"),
+            wxT("2022"),
             ProgramName)
         << wxT("<br>");
 #endif