[fix] delete trailing quote

searx/settings.yml

@@ -216,7 +216,7 @@ engines:
   - name : google scholar
     engine : xpath
     paging : True
-    search_url : https://scholar.google.com/scholar?start={pageno}&q={query}&hl=en&as_sdt=0,5&as_vis=1'
+    search_url : https://scholar.google.com/scholar?start={pageno}&q={query}&hl=en&as_sdt=0,5&as_vis=1
     results_xpath : //div[@class="gs_r"]/div[@class="gs_ri"]
     url_xpath : .//h3/a/@href
     title_xpath : .//h3/a