Up priority of yet another rule

Change-Id: Ifc7a19c6691e9f21b2e30264e12ac106028407cb
Reviewed-on: http://gerrit.dmdirc.com/2064
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Chris Smith <chris@dmdirc.com>

checkstyle/pmd_checks.xml

@@ -184,7 +184,7 @@
 <rule ref="rulesets/optimizations.xml/UseArraysAsList"><priority>1</priority></rule>
 <rule ref="rulesets/optimizations.xml/AvoidArrayLoops"><priority>1</priority></rule>
 <rule ref="rulesets/optimizations.xml/UnnecessaryWrapperObjectCreation"><priority>1</priority></rule>
-<rule ref="rulesets/optimizations.xml/AddEmptyString"><priority>2</priority></rule>
+<rule ref="rulesets/optimizations.xml/AddEmptyString"><priority>1</priority></rule>
 
 <rule ref="rulesets/strictexception.xml/AvoidCatchingThrowable"><priority>1</priority></rule>
 <rule ref="rulesets/strictexception.xml/SignatureDeclareThrowsException"><priority>1</priority></rule>