Remove unneeded check.

Check not needed since term is always in mapping.

Author: davidlehn

lib/context.js

@@ -799,9 +799,6 @@ api.getInitialContext = options => {
     const mappings = activeCtx.mappings;
     const terms = [...mappings.keys()].sort(_compareShortestLeast);
     for(const term of terms) {
-      if(!mappings.has(term)) {
-        continue;
-      }
       const mapping = mappings.get(term);
       if(mapping === null) {
         continue;