branch/3.5 Error: ...discards qualifiers

HI,

I get "discards qualifiers" error during compiling 
in /kdepim/kmail/messagecopyhelper.cpp +86
only the serialNumber needs to be const, but maybe it makes sens to make all 
getters const to get a consistent interface...

is it ok to commit this patch? or should I make all getters const?

Index: libkdepim/maillistdrag.h
===================================================================
--- libkdepim/maillistdrag.h    (revision 646854)
+++ libkdepim/maillistdrag.h    (working copy)
@@ -56,7 +56,7 @@ public:
     void set( Q_UINT32, QString, QString, QString, QString, time_t );

     /*** KMail unique identification number ***/
-    Q_UINT32 serialNumber();
+    Q_UINT32 serialNumber() const;

     /*** MD5 checksum of message identification string ***/
     QString messageId();
Index: libkdepim/maillistdrag.cpp
===================================================================
--- libkdepim/maillistdrag.cpp  (revision 646854)
+++ libkdepim/maillistdrag.cpp  (working copy)
@@ -37,7 +37,7 @@ MailSummary::MailSummary( Q_UINT32 seria
       mSubject( subject ), mFrom( from ), mTo( to ), mDate( date )
 {}

-Q_UINT32 MailSummary::serialNumber()
+Q_UINT32 MailSummary::serialNumber() const
 {
     return mSerialNumber;
 }