Corrected xpath syntax

https://ludeon.com/forums/index.php?topic=32785.msg335425#msg335425

Author: kaptain-kavern

Patches/patches.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <Patch>
 	<Operation Class="PatchOperationInsert">
-		<xpath>//IncidentDef[defName = "Disease_MuscleParasites"]/diseaseVictimFractionRange</xpath>
+		<xpath>/IncidentDefs/IncidentDef[defName = "Disease_MuscleParasites"]/diseaseVictimFractionRange</xpath>
 		<value>
 		    <diseasePartsToAffect>
 		      <li>Torso</li>