Fix grammar

Author: wchen-r7

modules/exploits/linux/http/github_enterprise_secret.rb

@@ -19,7 +19,7 @@ def initialize(info={})
         This module exploits two security issues in Github Enterprise, version 2.8. The first is
         that the session management uses a hard-coded secret value, which can be abused to sign
         a serialized malicious Ruby object. The second problem is due to the use of unsafe
-        deserialization, which can allows the malicious Ruby object to be loaded, and results
+        deserialization, which allows the malicious Ruby object to be loaded, and results
         in arbitrary remote code execution.
 
         This exploit was tested against version 2.8.0.