Don't show "deleted stale lock file" message by default.

The user typically can't do anything about this error anyhow, so don't show it
by default. Still do show it when running in the verbose mode as this might
add diagnosing the problem when something goes unexpectedly wrong.

Closes #15944.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75839 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/unix/snglinst.cpp

@@ -292,7 +292,13 @@ bool wxSingleInstanceCheckerImpl::Create(const wxString& name)
                 }
                 else
                 {
-                    wxLogMessage(_("Deleted stale lock file '%s'."),
+                    // This may be important to know if something goes
+                    // mysteriously wrong, but as the user can't really do
+                    // anything about here (the most typical reason for this
+                    // message is that the previous instance of the program
+                    // crashed), don't show it by default, i.e. unless the
+                    // program is running with --verbose command line option.
+                    wxLogInfo(_("Deleted stale lock file '%s'."),
                                  name.c_str());
 
                     // retry now