Fix T85395: Texture paint external edit wrong projection on reapply

Caused by rB5b34d11b55e0.

Above commit restored the view matrices in ED_view3d_draw_offscreen
_before_ they can be stored in the ImBuff (see ED_view3d_draw_offscreen
/ texture_paint_image_from_view_exec).

Now make restoring the view matrices optional and dont do this in case
of reprojection, so the used matrices can still be saved in the ImBuff
later.

Reviewed By: campbellbarton

Maniphest Tasks: T85395

Differential Revision: https://developer.blender.org/D10331

source/blender/editors/render/render_opengl.c

@@ -381,6 +381,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
                                                  imbuf_flags,
                                                  alpha_mode,
                                                  viewname,
+                                                 true,
                                                  oglrender->ofs,
                                                  err_out);