CONTRIB: Add vi file extensions to .gitignore

*.swp and *.swo file extensions are used by vi. Very annoying to not have them
ignored by git.

(cherry picked from commit 64d0ed515b10068dc21ac954fd2868d7f5d0e820)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 9131513ce3c6d5f4647d066e22ea5fb73277a1cf)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 8f296435d442ef1dc14b7abf20ae377751613dee)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 1e22de46ee0359d6886bbfd8853b25c719c08936)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/.gitignore b/.gitignore
index ec9dd62..62a92d1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,6 +38,7 @@
 *.rej
 *.orig
 *.bak
+*.sw[op]
 # And reject some specific files
 /admin/halog/halog
 /admin/dyncookie/dyncookie