bump year

Vladimir Kotal · Vladimir Kotal · commit e59e010c2545 · 2021-10-07T11:00:57.000+02:00
diff --git a/common.tex b/common.tex
@@ -1,5 +1,5 @@
 % Unix programming in C
-% (c) 1999-2019, Martin Beran, Jan Pechanec, Vladimir Kotal
+% (c) 1999-2021, Martin Beran, Jan Pechanec, Vladimir Kotal
 
 % (janp) notes
 %

Original file line number	Diff line number	Diff line change
`@@ -1,5 +1,5 @@`
`1`	`1`	`% Unix programming in C`
`2`		`-% (c) 1999-2019, Martin Beran, Jan Pechanec, Vladimir Kotal`
	`2`	`+% (c) 1999-2021, Martin Beran, Jan Pechanec, Vladimir Kotal`
`3`	`3`
`4`	`4`	`% (janp) notes`
`5`	`5`	`%`