use correct JNIParameterString

Author: michaelknoch

Sources/JNI/JavaParameterConvertible+Primitives.swift

@@ -111,7 +111,7 @@ extension Float: JavaParameterConvertible, JavaInitializableFromMethod, JavaInit
 // Int64 aka JavaFloat
 
 extension Int64: JavaParameterConvertible, JavaInitializableFromMethod, JavaInitializableFromField {
-    public static let asJNIParameterString = "L"
+    public static let asJNIParameterString = "J"
 
     public func toJavaParameter() -> JavaParameter {
         return JavaParameter(float: JavaFloat(self))