Avoid %z type character in string format

It triggers the following warning on MinGW:

    warning: unknown conversion type character 'z' in format [-Wformat=]

Since we don't expect the number of online players to go beyond
UINT_MAX, we can simply do a cast and use %u instead of %zu.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/gui/socialwindow.cpp b/src/gui/socialwindow.cpp
index 5a15da8f..37dc14dc 100644
--- a/src/gui/socialwindow.cpp
+++ b/src/gui/socialwindow.cpp
@@ -377,7 +377,7 @@ SocialWindow::SocialWindow() :
     mCreatePopup = new CreatePopup;
 
     mPlayerListTab = new PlayerListTab;
-    mPlayerListTab->setCaption(strprintf(_("Online (%zu)"), 0ul));
+    mPlayerListTab->setCaption(strprintf(_("Online (%u)"), 0u));
 
     mTabs->addTab(mPlayerListTab, mPlayerListTab->mScroll.get());
 
@@ -673,7 +673,9 @@ void SocialWindow::showPartyCreate()
 void SocialWindow::setPlayersOnline(const std::vector<Avatar*> &players)
 {
     mPlayerListTab->setPlayers(players);
-    mPlayerListTab->setCaption(strprintf(_("Online (%zu)"), players.size()));
+
+    unsigned playerCount = static_cast<unsigned>(players.size());
+    mPlayerListTab->setCaption(strprintf(_("Online (%u)"), playerCount));
 }
 
 void SocialWindow::logic()