Fix symfony 5.3 deprecation

Since Symfony 5.3 is deprecated to construct PropertyAccessor with
a bool value as second argument.

Ref: https://github.com/symfony/property-access/blob/8988399a556cffb0fba9bb3603f8d1ba4543eceb/CHANGELOG.md#530

Author: franmomu

src/Resources/config/config.xml

@@ -6,7 +6,7 @@
 
     <parameters>
         <parameter key="fos_elastica.property_accessor.magicCall">0</parameter>
-        <parameter key="fos_elastica.property_accessor.throwExceptionOnInvalidIndex">false</parameter>
+        <parameter key="fos_elastica.property_accessor.throwExceptionOnInvalidIndex">0</parameter>
     </parameters>
 
     <services>