Fix displaying of web history if limited to -1.

This is a regression introduced in 2aa7e5bb35.
Fixes #991.

CHANGELOG.asciidoc

@@ -36,6 +36,11 @@ Changed
 - The `colors -> tabs.bg/fg.selected` option got split into
   `tabs.bg/fg.selected.odd/even`.
 
+Fixed
+~~~~~
+
+- Fixed displaying of web history if `web-history-max-items` is set to -1.
+
 v0.4.1
 ------
 

qutebrowser/completion/models/urlmodel.py

@@ -102,7 +102,8 @@ class UrlCompletionModel(base.BaseCompletionModel):
                       self._fmt_atime(entry.atime), sort=int(entry.atime),
                       userdata=entry.url)
 
-        if self._history_cat.rowCount() > self._max_history:
+        if (self._max_history != -1 and
+                self._history_cat.rowCount() > self._max_history):
             self._remove_oldest_history()
 
     @config.change_filter('completion', 'timestamp-format')