Remove unused the_previousVersion

src/kmkernel.cpp

@@ -1000,8 +1000,6 @@ void KMKernel::init()
 
     the_firstStart = KMailSettings::self()->firstStart();
     KMailSettings::self()->setFirstStart(false);
-    the_previousVersion = KMailSettings::self()->previousVersion();
-    KMailSettings::self()->setPreviousVersion(QStringLiteral(KDEPIM_VERSION));
 
     the_undoStack = new KMail::UndoStack(20);
 
@@ -1882,11 +1880,6 @@ bool KMKernel::firstStart() const
     return the_firstStart;
 }
 
-QString KMKernel::previousVersion() const
-{
-    return the_previousVersion;
-}
-
 bool KMKernel::shuttingDown() const
 {
     return the_shuttingDown;

src/kmkernel.h

@@ -346,7 +346,6 @@ public:
     void expireAllFoldersNow();
 
     bool firstStart() const;
-    QString previousVersion() const;
     bool shuttingDown() const;
     void setShuttingDown(bool flag);
 
@@ -491,9 +490,6 @@ private:
 
     KMail::UndoStack *the_undoStack = nullptr;
     MessageComposer::AkonadiSender *the_msgSender = nullptr;
-    /** previous KMail version. If different from current,
-      the user has just updated. read from config */
-    QString the_previousVersion;
     /** is this the first start?  read from config */
     bool the_firstStart = false;
     /** are we going down? set from here */

src/settings/kmail.kcfg.cmake

@@ -122,10 +122,6 @@
         <label>Specifies whether this is the very first time that the application is run (for internal use only)</label>
         <default>true</default>
       </entry>
-      <entry name="PreviousVersion" type="String" key="previous-version">
-        <label>Specifies the version of the application that was last used (for internal use only)</label>
-        <default code="true">QLatin1String(KDEPIM_VERSION)</default>
-      </entry>
       <entry key="ShowMenuBar" type="Bool">
         <default>true</default>
          <!-- label and whatsthis are already provided by KStandardAction::showMenubar -->