Fix headless build on Linux

Conditional-compile some OpenGL-ness that crept in

Change-Id: I8d12f34db3b4875470a0d81e9ef6a1654153b206
Reviewed-on: https://gerrit.libreoffice.org/63676
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

vcl/headless/svpinst.cxx

@@ -28,7 +28,9 @@
 #include <sal/log.hxx>
 
 #include <vcl/inputtypes.hxx>
-#include <vcl/opengl/OpenGLContext.hxx>
+#ifndef LIBO_HEADLESS
+# include <vcl/opengl/OpenGLContext.hxx>
+#endif
 
 #include <headless/svpinst.hxx>
 #include <headless/svpframe.hxx>

vcl/source/outdev/text.cxx

@@ -35,7 +35,9 @@
 #include <vcl/sysdata.hxx>
 #include <vcl/unohelp.hxx>
 #include <vcl/controllayout.hxx>
-#include <vcl/opengl/OpenGLHelper.hxx>
+#ifdef MACOSX
+# include <vcl/opengl/OpenGLHelper.hxx>
+#endif
 
 #include <outdata.hxx>
 #include <outdev.h>