Deleting everything except the wallet will not help recover from BDB errors.

Now that the wallet is the only thing in BDB any DB open errors must be
from the wallet itself-- so deleting everything else will not likely help.

src/init.cpp

@@ -612,9 +612,7 @@ bool AppInit2()
 
     if (!bitdb.Open(GetDataDir()))
     {
-        string msg = strprintf(_("Error initializing database environment %s!"
-                                 " To recover, BACKUP THAT DIRECTORY, then remove"
-                                 " everything from it except for wallet.dat."), strDataDir.c_str());
+        string msg = strprintf(_("Error initializing wallet database environment %s!"), strDataDir.c_str());
         return InitError(msg);
     }