Update lib_amp.ssjs

Fixed missing ',' based on issue #8

Author: shdinx

core/lib_amp.ssjs

@@ -228,7 +228,7 @@ function SHA1(string,encoding) {
  // parameters
  amp += "'" + string + "'";
  if(encoding) {
- amp += "'" + encoding + "'";
+ amp += ",'" + encoding + "'";
  }
  // function close
  amp += ") ";
@@ -262,7 +262,7 @@ function SHA256(string,encoding) {
  // parameters
  amp += "'" + string + "'";
  if(encoding) {
- amp += "'" + encoding + "'";
+ amp += ",'" + encoding + "'";
  }
  // function close
  amp += ") ";
@@ -296,7 +296,7 @@ function SHA512(string,encoding) {
  // parameters
  amp += "'" + string + "'";
  if(encoding) {
- amp += "'" + encoding + "'";
+ amp += ",'" + encoding + "'";
  }
  // function close
  amp += ") ";
@@ -508,4 +508,4 @@ function GetJWTByKeyName(key,algorithm,payload) {
  amp += "]\%\%";
 
  return Platform.Function.TreatAsContent(amp);
-}
+}