Mail and Notification prefs: use B_WIDTH_FROM_WIDEST

Spotted by Diver: missing B_WIDTH_FROM_WIDEST for the BTabViews
resulted in labels being vut off with bigger font settings.

src/preferences/mail/ConfigWindow.cpp

@@ -208,7 +208,7 @@ ConfigWindow::ConfigWindow()
 	fLastSelectedAccount(NULL),
 	fSaveSettings(false)
 {
-	BTabView* tabView = new BTabView("tab");
+	BTabView* tabView = new BTabView("tab", B_WIDTH_FROM_WIDEST);
 	tabView->SetBorder(B_NO_BORDER);
 
 	// accounts listview

src/preferences/notifications/PrefletView.cpp

@@ -30,7 +30,7 @@ const int32 kPageSelected = '_LCH';
 
 PrefletView::PrefletView(SettingsHost* host)
 	:
-	BTabView("pages")
+	BTabView("pages", B_WIDTH_FROM_WIDEST)
 {
 	// Pages
 	GeneralView* general = new GeneralView(host);