allow cover commands to work with glossary entries

cover.tex

@@ -5,8 +5,8 @@
 % commands. We resolve this with a little white lie.
 \newcommand\glsentrylongpl{}
 \newcommand\glsentrytext{}
-\newcommand\Glsfmtplural{}
-\newcommand\Glsfmtlongpl{}
+\newcommand\Glsfmtplural[1]{\MakeUppercase#1s}
+\newcommand\Glsfmtlongpl[1]{\MakeUppercase#1s}
 \newcommand\Gls{}
 \newcommand\Glsfmttext{}
 \newcommand\gls{}