Update ergom_zoo.F90

[harshalchauhan18]

No description provided.

[harshalchauhan18]

Added DIC release by the zooplankton excretion.

[jornbr]

Thanks for updating the uhh code. My main comment on this pull requests and the others, however, is that you're reverted preprocessor macros like _ADD_SOURCE_ to their old, deprecated version (in this case, _SET_ODE_). That's not a good idea, as those old macros will be removed in the next FABM version. Similarly, you're still working with namelists in your initialize routines, but the current FABM version does not read those anymore, so there is certainly no need to extend them. Instead, it would be better to remove them altogether.