screen: critical security fix for #5603

We revert the critical hunk for now.

setgid yet needs to be figured out, as screen can then not create
/run/screens itself.

srcpkgs/screen/patches/revert-c575c40c.patch

@@ -0,0 +1,15 @@
+--- screen.c.orig
++++ screen.c
+@@ -673,12 +673,6 @@
+                 Panic(0, "-L: logfile name can not start with \"-\" symbol");
+               if (strlen(screenlogfile) > PATH_MAX)
+                 Panic(0, "-L: logfile name too long. (max. %d char)", PATH_MAX);
+-
+-              FILE *w_check;
+-              if ((w_check = fopen(screenlogfile, "w")) == NULL)
+-                Panic(0, "-L: logfile name access problem");
+-              else
+-                fclose(w_check);
+             }
+             nwin_options.Lflag = 1;
+             break;

srcpkgs/screen/template

@@ -1,7 +1,7 @@
 # Template file for 'screen'
 pkgname=screen
 version=4.5.0
-revision=1
+revision=2
 build_style=gnu-configure
 configure_args="--with-sys-screenrc=/etc/screenrc --enable-pam
  --enable-colors256 --enable-rxvt_osc --enable-telnet