[rapidxml-package] add trailing newline to PackageInfo.json

Signed-off-by: AMZN-ScottR <[email protected]>

package-system/RapidXML-multiplatform/PackageInfo.json

@@ -3,4 +3,4 @@
     "URL"         : "http://rapidxml.sourceforge.net/",
     "License"     : "MIT",
     "LicenseFile" : "RapidXML/include/rapidxml/license.txt"
-}
+}