removed useless + that fobuid compilation

cours.tex

-+% Copyright (C)  2016  Orestis Malaspinas.
-+%     Permission is granted to copy, distribute and/or modify this document
-+%     under the terms of the GNU Free Documentation License, Version 1.3
-+%     or any later version published by the Free Software Foundation;
-+%     with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
-+%     A copy of the license can be downloaded from:
-+%     https://www.gnu.org/licenses/fdl.html.
+% Copyright (C)  2016  Orestis Malaspinas.
+%     Permission is granted to copy, distribute and/or modify this document
+%     under the terms of the GNU Free Documentation License, Version 1.3
+%     or any later version published by the Free Software Foundation;
+%     with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
+%     A copy of the license can be downloaded from:
+%     https://www.gnu.org/licenses/fdl.html.
 
 \documentclass[a4paper,12pt]{book}
 \usepackage[utf8]{inputenc}