Gemfile.lock: update nokogiri

Fixes CVE-2020-26247

Gemfile.lock

@@ -89,7 +89,7 @@ GEM
     iniparse (1.4.4)
     ipaddress (0.8.3)
     libyajl2 (1.2.0)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.5.0)
     minitar (0.9)
     mixlib-archive (1.0.5)
       mixlib-log
@@ -113,8 +113,9 @@ GEM
       net-ssh (>= 2.6.5)
       net-ssh-gateway (>= 1.2.0)
     net-telnet (0.1.1)
-    nokogiri (1.10.8)
-      mini_portile2 (~> 2.4.0)
+    nokogiri (1.11.1)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
     octokit (4.15.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
@@ -134,6 +135,7 @@ GEM
     polyglot (0.3.5)
     proxifier (1.0.3)
     public_suffix (4.0.3)
+    racc (1.5.2)
     rack (2.2.3)
     rake (13.0.1)
     retryable (3.0.5)