update info string in GUI for generated blocks and change "must wait" into "must mature" to take the new immature label into consideration

src/qt/transactiondesc.cpp

@@ -226,7 +226,7 @@ QString TransactionDesc::toHTML(CWallet *wallet, CWalletTx &wtx)
         strHTML += QString("<b>") + tr("Transaction ID:") + "</b> " + wtx.GetHash().ToString().c_str() + "<br>";
 
         if (wtx.IsCoinBase())
-            strHTML += QString("<br>") + tr("Generated coins must wait 120 blocks before they can be spent.  When you generated this block, it was broadcast to the network to be added to the block chain.  If it fails to get into the chain, it will change to \"not accepted\" and not be spendable.  This may occasionally happen if another node generates a block within a few seconds of yours.") + "<br>";
+            strHTML += QString("<br>") + tr("Generated coins must mature 120 blocks before they can be spent. When you generated this block, it was broadcast to the network to be added to the block chain. If it fails to get into the chain, it's state will change to \"not accepted\" and it won't be spendable. This may occasionally happen if another node generates a block within a few seconds of yours.") + "<br>";
 
         //
         // Debug view

src/qt/transactiontablemodel.cpp

@@ -298,8 +298,7 @@ QString TransactionTableModel::formatTxStatus(const TransactionRecord *wtx) cons
         switch(wtx->status.maturity)
         {
         case TransactionStatus::Immature:
-            status += "\n" + tr("Mined balance will be available in %n more blocks", "",
-                           wtx->status.matures_in);
+            status += "\n" + tr("Mined balance will be available when it matures in %n more block(s)", "", wtx->status.matures_in);
             break;
         case TransactionStatus::Mature:
             break;