[evince] shell: Fix regression on Ctrl+PageUp/PageDown shortcuts

[Germán Poo-Caamaño <gpoo src gnome org>]

commit d2b804f48514b4a52800ee7af67954eef3b65b47
Author: Germán Poo-Caamaño <gpoo gnome org>
Date:   Thu Jun 28 16:21:38 2018 -0400

    shell: Fix regression on Ctrl+PageUp/PageDown shortcuts
    
    Ctrl+PageUp and Ctrl+PageDown used to be used for navigating to
    the previous and next page, respectively. With the migration from
    old toolbars to the headerbar, these shortcuts were lost.
    
    commit 8bb5fce0 removed them, likely it was an oversight.
    
    Closes #699

 shell/ev-application.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/shell/ev-application.c b/shell/ev-application.c
index fcbcaa75..9bb7a066 100644
--- a/shell/ev-application.c
+++ b/shell/ev-application.c
@@ -1058,8 +1058,8 @@ ev_application_startup (GApplication *gapplication)
           "win.select-page",            "<Ctrl>L", NULL,
           "win.go-backwards",           "<Shift>Page_Up", NULL,
           "win.go-forward",             "<Shift>Page_Down", NULL,
-          "win.go-next-page",           "n", NULL,
-          "win.go-previous-page",       "p", NULL,
+          "win.go-next-page",           "n", "<Ctrl>Page_Down", NULL,
+          "win.go-previous-page",       "p", "<Ctrl>Page_Up", NULL,
           "win.go-back-history",        "<alt>P", "Back", NULL,
           "win.go-forward-history",     "<alt>N", "Forward", NULL,
           "win.sizing-mode::fit-page",  "f", NULL,