save TR in output files

fsl_regfilt.cc

@@ -112,6 +112,7 @@ void save4D(Matrix what, string fname){
 				tempVol.setmatrix(what.t(),mask);
 			else
 				tempVol.setmatrix(what,mask);
+			tempVol.setTR(TR);
 			save_volume4D(tempVol,fname);
 		}
 }