Update net-imap gem version in versions.json

Author: andrykonchin

versions.json

@@ -16,7 +16,7 @@
       "matrix": "0.4.2",
       "minitest": "5.20.0",
       "net-ftp": "0.3.4",
-      "net-imap": "0.4.9.1",
+      "net-imap": "0.4.19",
       "net-pop": "0.1.2",
       "net-smtp": "0.4.0.1",
       "power_assert": "2.0.3",