SOFAexpand: creates error when used in SOFAmerge

[isfmiho]

Reproduce issue when running demo_SOFAmerge in SOFA Toolbox v2.4.1.

Script creates the following output:

Merging to a single SOFA object
Unable to perform assignment with 0 elements on the right-hand side.
Error in SOFAexpand>expand (line 140)
        dN=dims{cellfun('isempty',strfind(dims,'I'))==1};
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error in SOFAexpand (line 105)
                    [varNew,dimNew]=expand(Obj,VarName,dim);
                                    ^^^^^^^^^^^^^^^^^^^^^^^
Error in SOFAmerge (line 70)
				AExp=SOFAexpand(A,Bf{ii});
         ^^^^^^^^^^^^^^^^^^^^
Error in demo_SOFAmerge (line 41)
	ObjFull=SOFAmerge(ObjFull,Obj(ii));
         ^^^^^^^^^^^^^^^^^^^^^^^^^^ 

The expand command has been modified to fix other issues. It created a new bug.