Correct the default Logback config location in the documentation

Fixes #1247

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -43,7 +43,7 @@ content into your application; rather pick only the properties that you need.
 	# LOGGING
 	logging.path=/var/logs
 	logging.file=myapp.log
-	logging.config= # location of config file (default classpath:/logback.xml for logback)
+	logging.config= # location of config file (default classpath:logback.xml for logback)
     logging.level.*= # levels for loggers, e.g. "logging.level.org.springframework=DEBUG" (TRACE, DEBUG, INFO, WARN, ERROR, FATAL, OFF)
 
 	# IDENTITY ({sc-spring-boot}/context/ContextIdApplicationContextInitializer.{sc-ext}[ContextIdApplicationContextInitializer])

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -868,7 +868,7 @@ You can also set the location of a file to log to (in addition to the console) u
 To configure the more fine grained settings of a logging system you need to use the native
 configuration format supported by the `LoggingSystem` in question. By default Spring Boot
 picks up the native configuration from its default location for the system (e.g.
-`classpath:/logback.xml` for Logback), but you can set the location of the config file
+`classpath:logback.xml` for Logback), but you can set the location of the config file
 using the "logging.config" property.