Bump limit in compile output to 50k

A project of qt's size generates 13k of output. That's without cleaning
and a project which compiles mostly warning free. So expecting 50.000 of
output seems reasonable, might even be a little too low.

src/plugins/projectexplorer/compileoutputwindow.cpp

@@ -50,7 +50,7 @@ using namespace ProjectExplorer;
 using namespace ProjectExplorer::Internal;
 
 namespace {
-const int MAX_LINECOUNT = 10000;
+const int MAX_LINECOUNT = 50000;
 }
 
 CompileOutputWindow::CompileOutputWindow(BuildManager * /*bm*/)