Update manpage for renamed check

debian/patches/for-upstream/2020-12-28.install-as-check-tang.patch

@@ -36,3 +36,23 @@ Bug: https://github.com/latchset/nagios-tang/issues/2
  
 -tang -u http://127.0.0.1:$port
 +check_tang -u http://127.0.0.1:$port
+--- a/nagios-tang.1.adoc
++++ b/nagios-tang.1.adoc
+@@ -4,7 +4,7 @@
+ 
+ == NAME
+ 
+-nagios-tang - A Nagios plugin for Tang
++check_tang - A Nagios plugin for Tang
+ 
+ == SYNOPSIS
+ 
+@@ -36,7 +36,7 @@
+ 
+ A simple test against a localhost Tang server:
+ 
+-    $ ./tang -u http://localhost/
++    $ check_tang -u http://localhost/
+     OK|adv=21430 exc=44587 nkeys=2 nsigk=1 nexck=1
+ 
+ == AUTHOR