Update comment following the switch to Meson

[skip ci]

src/initialize_dseries_class.m

@@ -113,7 +113,7 @@ if isempty(select_x13_binary(true))
 end
 
 % The following version requirement should not be stricter than the one in
-% Dynare (matlab/dynare.m and mex/build/octave/configure.ac)
+% Dynare (matlab/dynare.m and meson.build)
 if isoctave && octave_ver_less_than('6.2.0')
     skipline()
     warning(['This version of dseries has only been tested on Octave 6.2.0 and above. It may fail to run or give unexpected result. Consider upgrading your version of Octave.'])