chore(pmd): enable a couple of new rules from PMD 6.4.0

Quote from https://pmd.github.io/2018/05/29/PMD-6.4.0/#new-rules
%
The new Java rule HardCodedCryptoKey (java-security) detects hard coded keys used for encryption. It
is recommended to store keys outside of the source code.

The new Java rule IdenticalCatchBranches (java-codestyle) finds catch blocks, that catch different
exception but perform the same exception handling and thus can be collapsed into a multi-catch try
statement.
%

Author: php-coder

src/main/config/pmd.xml

@@ -89,6 +89,7 @@
 	<rule ref="category/java/codestyle.xml/FieldDeclarationsShouldBeAtStartOfClass" />
 	<rule ref="category/java/codestyle.xml/ForLoopShouldBeWhileLoop" />
 	<rule ref="category/java/codestyle.xml/GenericsNaming" />
+	<rule ref="category/java/codestyle.xml/IdenticalCatchBranches" />
 	<!--<rule ref="category/java/codestyle.xml/LocalHomeNamingConvention" />-->
 	<!--<rule ref="category/java/codestyle.xml/LocalInterfaceSessionNamingConvention" />-->
 	<!--<rule ref="category/java/codestyle.xml/LocalVariableCouldBeFinal" />-->
@@ -316,6 +317,7 @@
 	<rule ref="category/java/performance.xml/UseStringBufferForStringAppends" />
 	<rule ref="category/java/performance.xml/UseStringBufferLength" />
 
+	<rule ref="category/java/security.xml/HardCodedCryptoKey" />
 	<rule ref="category/java/security.xml/InsecureCryptoIv" />
 
 </ruleset>