Update replica-set-priority-0-member.txt

Author: trevorprater

source/core/replica-set-priority-0-member.txt

@@ -24,7 +24,7 @@ acknowledging write operations with ``"majority"`` write concern.
 
 Other than the aforementioned restrictions, secondaries that have
 :rsconf:`priority 0 <members[n].priority>` function as normal
-secondaries: they maintains a copy of the data set, accept read
+secondaries: they maintain a copy of the data set, accept read
 operations, and vote in elections.
 
 Configure a secondary to have *priority 0* to prevent it from