small doc fix as raised by issue #562 (#641)

doc/source/components/sink/sink_par.csv

@@ -1,7 +1,7 @@
 **Parameter**;**Datatype**;**Value Range**;**Explanation**
 name;string;;Name of the sink
 junction;integer;;Index of connected junction
-mdot_kg_per_s;float;:math:`\leq 0`;Drawn mass flow [kg/s]
+mdot_kg_per_s;float;:math:`\geq 0`;Drawn mass flow [kg/s]
 scaling *;float;:math:`\geq 0`;Scaling factor to adapt the drawn mass flow
 in_service*;boolean;True / False;Specifies if the sink is in service.
 type;string;;Component type