Use single quotes consistently

lib/msf/core/payload/java.rb

@@ -17,7 +17,7 @@ module Msf::Payload::Java
   def generate_stage
     stage = ''
     @stage_class_files.each do |path|
-      data = MetasploitPayloads.read("java", path)
+      data = MetasploitPayloads.read('java', path)
       stage << ([data.length].pack("N") + data)
     end
     stage << [0].pack("N")

modules/exploits/multi/http/axis2_deployer.rb

@@ -98,7 +98,7 @@ class Metasploit3 < Msf::Exploit::Remote
 
       # We need this class as a wrapper to run in a thread.  For some reason
       # the Payload class is giving illegal access exceptions without it.
-      servlet = MetasploitPayloads.read("java", "metasploit", "PayloadServlet.class")
+      servlet = MetasploitPayloads.read('java', 'metasploit', 'PayloadServlet.class')
       zip.add_file("metasploit/PayloadServlet.class", servlet)
 
       contents = zip.pack