FIX: Reduce number of terms injected for host lexeme.

We do prefix matching in search so there is no need to inject the extra
terms.

Before:
```
"'discourse':10,11 'discourse.org':10,11 'org':10,11 'test':8A,10,11 'test.discourse.org':10,11 'titl':4A 'uncategor':9B"
```

After:
```
"'discourse.org':10,11 'org':10,11 'test':8A 'test.discourse.org':10,11 'titl':4A 'uncategor':9B"
```

app/services/search_indexer.rb

@@ -65,7 +65,7 @@ class SearchIndexer
           break if count >= 10 # Safeguard here to prevent infinite loop when a term has many dots
           term, _, remaining = lexeme.partition(".")
           break if remaining.blank?
-          array << "'#{term}':#{positions} '#{remaining}':#{positions}"
+          array << "'#{remaining}':#{positions}"
           lexeme = remaining
         end
       end