also escape ~ char before sending to sphinx

app/models/search.rb

@@ -59,10 +59,8 @@ class Search
         []
       end
 
-    # sphinx seems to interpret slashes as a regex(?) so escape them since
-    # nobody is probably using them, but don't just use Riddle.escape because
-    # it removes boolean suport
-    query = self.q.gsub(/\//, "\\/")
+    # escape sphinx special chars (using Riddle.escape removes boolean support)
+    query = self.q.gsub(/([\/~])/, '\\\\\1')
 
     # go go gadget search
     @results = []