Warning on start Alfresco Community 3.4

[redbull]

Hi.
On start Alfresco the log file contains:

15:29:15,968  WARN  [springframework.beans.GenericTypeAwarePropertyDescriptor] Invalid JavaBean property 'blockedSenders' being accessed! Ambiguous write methods found next to actually used [public void org.alfresco.email.server.EmailServer.setBlockedSenders(java.lang.String)]: [public void org.alfresco.email.server.EmailServer.setBlockedSenders(java.util.List)]15:29:15,968  WARN  [springframework.beans.GenericTypeAwarePropertyDescriptor] Invalid JavaBean property 'allowedSenders' being accessed! Ambiguous write methods found next to actually used [public void org.alfresco.email.server.EmailServer.setAllowedSenders(java.util.List)]: [public void org.alfresco.email.server.EmailServer.setAllowedSenders(java.lang.String)]‍‍‍

What is? How can I solve this warning?
Thanks to all.

[mrogers]

You can't fix this without changes to the code.    It's already fixed in some versions.

[redbull]

You can't fix this without changes to the code.    It's already fixed in some versions.

and then? What is the version that resolve these warnings? I'm using the last one, 3.4c
a little help to solve this puzzle…
thanks