ChanViewer: Use pledge()

This app should be ported to LibProtocol, which would allow it to drop
"inet" and "dns" as well.

Applications/ChanViewer/main.cpp

@@ -10,11 +10,22 @@
 #include <LibGUI/GStatusBar.h>
 #include <LibGUI/GTableView.h>
 #include <LibGUI/GWindow.h>
+#include <stdio.h>
 
 int main(int argc, char** argv)
 {
+    if (pledge("stdio dns inet shared_buffer rpath cpath fattr", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
     GApplication app(argc, argv);
 
+    if (pledge("stdio dns inet shared_buffer rpath", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
     auto window = GWindow::construct();
     window->set_title("ChanViewer");
     window->set_rect(100, 100, 800, 500);