Fix build with GCC 10.
a5294cbbfd90e7b7b2c3c69186d6e67ba12bc913

Index: troff/n5.c
--- troff/n5.c.orig
+++ troff/n5.c
@@ -1588,8 +1588,6 @@ caseie(void)
 	caseif(1);
 }
 
-int	tryglf;
-
 void
 caseif(int x)
 {