Omollo:
I don't see that happening. But, purely as an "academic" exercise:
* It might be considered that a president who is locked up in a far-away land is "physically incapable" of carrying out his duties. In that case the National Assembly would initiate a process to kick him out, under Article 144. I do, however, believe that the relevant clause is intended to cover "physical illness", not being nabbed for crimes, but I imagine it could be stretched.
* An ICC arrest warrant would be issued for, say, obstruction of justice. In this case the National Assembly could seek to kick him out because there would be "serious reasons for believing that the President has committed a crime under national or international law". (Article 145)