bug #155 add missing config option to XSD file (xabbuh)

This PR was squashed before being merged into the 2.8.x-dev branch (closes #155).

Discussion
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add missing config option to XSD file

This option was introduced in #153.

Commits
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ef846fb add missing config option to XSD file

Resources/config/schema/monolog-1.0.xsd

@@ -71,6 +71,7 @@
         <xsd:attribute name="document-type" type="xsd:string" />
         <xsd:attribute name="ignore-error" type="xsd:string" />
         <xsd:attribute name="api_version" type="xsd:string" />
+        <xsd:attribute name="include-stacktraces" type="xsd:string" />
     </xsd:complexType>
 
     <xsd:simpleType name="level">