[doc][handbook] Change package name scrpage2 to newer version scrlayer-scrpage.

doc/docextra/3dmpfa/MpfaGuide.tex

@@ -20,7 +20,7 @@
 
 \usepackage{lmodern}
 
-\usepackage{scrpage2}
+\usepackage{scrlayer-scrpage}
 \usepackage{amsmath}
 \usepackage{amssymb}
 \usepackage{graphicx}

doc/handbook/0_dumux-handbook.tex

@@ -2,7 +2,7 @@
 \usepackage[usenames,dvipsnames,table]{xcolor} % include at beginning because of compitibility issues
 \usepackage[english]{babel}
 \usepackage[utf8]{inputenc}
-\usepackage[automark]{scrpage2}
+\usepackage[automark]{scrlayer-scrpage}
 \usepackage[normalem]{ulem}
 \usepackage{amsmath}
 \usepackage{amsfonts}