update quality gate description

sonar-core/src/main/resources/org/sonar/l10n/core.properties

@@ -1873,7 +1873,7 @@ quality_gates.conditions.operator=Operator
 quality_gates.conditions.warning=Warning
 quality_gates.conditions.error=Error
 quality_gates.duplicated_conditions=This quality gate has duplicated conditions:
-quality_gates.intro.1=Quality Gates are collections of simple boolean thresholds set on project measures. A project must pass each of the thresholds in order to pass the Quality Gate as a whole.
+quality_gates.intro.1=Quality Gate is the set of conditions the project must meet before it can be released into production.
 quality_gates.intro.2=It is possible to set a default Quality Gate, which will be applied to all projects not explicitly assigned to some other gate.
 
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