zuul-*: use multiline formatter

Zuul change I6d7e7e7a9e19d46a744f9ffac8d532fc6b4bba01 introduced a
multi-line formatter that makes exceptions and other multi-line output
much easier to follow in the logs.  Use it here for the simple
formatter in the production Zuul deployment.

Change-Id: I9a8aad8a90f5f4080cdb872d0ed65697a180f57c

playbooks/roles/zuul-executor/files/logging.conf

@@ -47,3 +47,4 @@ args=('/var/log/zuul/executor.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter

playbooks/roles/zuul-merger/files/logging.conf

@@ -47,3 +47,4 @@ args=('/var/log/zuul/merger.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter

playbooks/roles/zuul-scheduler/files/gearman-logging.conf

@@ -31,3 +31,4 @@ args=('/var/log/zuul/gearman-server.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter

playbooks/roles/zuul-scheduler/files/logging.conf

@@ -62,3 +62,4 @@ args=('/var/log/zuul/zuul.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter

playbooks/roles/zuul-web/files/fingergw-logging.conf

@@ -47,3 +47,4 @@ args=('/var/log/zuul/fingergw.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter

playbooks/roles/zuul-web/files/logging.conf

@@ -52,3 +52,4 @@ args=('/var/log/zuul/web.log',)
 [formatter_simple]
 format=%(asctime)s %(levelname)s %(name)s: %(message)s
 datefmt=
+class=zuul.lib.logutil.MultiLineFormatter