--enable-ext-mariadb-connector was removed

...in 26b40fcfc67480e75bd9959b0c5cb9db10fdf6a1 "Moving mysqlc into connectivity
as a library", apparently without replacement

Change-Id: Ia1d32f98bd90efe2fcd4441dd84cd1862a4daa70
diff --git a/distro-configs/Jenkins/Linux_ubsan_master.conf b/distro-configs/Jenkins/Linux_ubsan_master.conf
index 5a58959..74a4dbf 100644
--- a/distro-configs/Jenkins/Linux_ubsan_master.conf
+++ b/distro-configs/Jenkins/Linux_ubsan_master.conf
@@ -7,7 +7,6 @@
--enable-evolution2
--enable-ext-ct2n
--enable-ext-languagetool
--enable-ext-mariadb-connector
--with-system-mariadb
--enable-ext-nlpsolver
--enable-ext-numbertext