add time range strings to be translated

searx/templates/oscar/time-range.html

 <!-- Time range -->
 <div class="input-group">
     <input type="radio" id="time-range-anytime" name="time_range" value="" {{ "checked" if time_range=="" or not time_range  else ""}}>
-    <label for="time-range-anytime" class="input-group-addon">Anytime</label>
+    <label for="time-range-anytime" class="input-group-addon">{{ _('Anytime') }}</label>
     <input type="radio" id="time-range-day" name="time_range" value="day" {{ "checked" if time_range=="day" else ""}}>
-    <label for="time-range-day" class="input-group-addon">Last day</label>
+    <label for="time-range-day" class="input-group-addon">{{ _('Last day') }}</label>
     <input type="radio" id="time-range-week" name="time_range" value="week" {{ "checked" if time_range=="week" else ""}}>
-    <label for="time-range-week" class="input-group-addon">Last week</label>
+    <label for="time-range-week" class="input-group-addon">{{ _('Last week') }}</label>
     <input type="radio" id="time-range-month" name="time_range" value="month" {{ "checked" if time_range=="month" else ""}}>
-    <label for="time-range-month" class="input-group-addon">Last month</label>
+    <label for="time-range-month" class="input-group-addon">{{ _('Last month') }}</label>
 </div>