corrcoef is included in Octave 4.4

(manually cherry picked from commit c7a57e59)

matlab/dynare_config.m

@@ -106,8 +106,8 @@ if isoctave && octave_ver_less_than('4.0')
     p{end+1} = '/missing/ilu';
 end
 
-% corrcoef with two outputs is missing in Octave (ticket #796)
-if isoctave && ~user_has_octave_forge_package('nan')
+% corrcoef with two outputs is missing in Octave < 4.4 (ticket #796)
+if isoctave && octave_ver_less_than('4.4') && ~user_has_octave_forge_package('nan')
     p{end+1} = '/missing/corrcoef';
 end