ignore unredirection configuration on intel

the only thing it does on these systems is cause users
trouble because usually when there's a client where
unredirection makes sense, that uses OpenGL - and then
things break in the driver.

CCBUG: 252817
REVIEW: 111476

eglonxbackend.cpp

@@ -72,6 +72,8 @@ void EglOnXBackend::init()
     }
     GLPlatform *glPlatform = GLPlatform::instance();
     glPlatform->detect(EglPlatformInterface);
+    if (GLPlatform::instance()->driver() == Driver_Intel)
+        options->setUnredirectFullscreen(false); // bug #252817
     glPlatform->printResults();
     initGL(EglPlatformInterface);
     if (!hasGLExtension("GL_OES_EGL_image")) {

glxbackend.cpp

@@ -95,6 +95,8 @@ void GlxBackend::init()
     // Initialize OpenGL
     GLPlatform *glPlatform = GLPlatform::instance();
     glPlatform->detect(GlxPlatformInterface);
+    if (GLPlatform::instance()->driver() == Driver_Intel)
+        options->setUnredirectFullscreen(false); // bug #252817
     glPlatform->printResults();
     initGL(GlxPlatformInterface);
     // Check whether certain features are supported

options.cpp

@@ -651,6 +651,8 @@ void Options::setHiddenPreviews(int hiddenPreviews)
 
 void Options::setUnredirectFullscreen(bool unredirectFullscreen)
 {
+    if (GLPlatform::instance()->driver() == Driver_Intel)
+        unredirectFullscreen = false; // bug #252817
     if (m_unredirectFullscreen == unredirectFullscreen) {
         return;
     }