Annotator: simplified try...catch() statements.
Annotator: simplified try...catch() statements.

Thus ends up being consistent with the other try...catch() statements `src/annotator.cpp`.

hsorby/libcellml,cellml/libcellml,cellml/libcellml,hsorby/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,hsorby/libcellml,nickerso/libcellml,cellml/libcellml,nickerso/libcellml,nickerso/libcellml