Update developer-guide.adoc
Typo: "created created" (twice)
This closes
@@ -1455,7 +1455,7 @@ The appropriate data is then copied from the InputStream of the
original FlowFile to the OutputStream for the new FlowFile.
*Clone Method*
-If the content of the newly created created FlowFile is to be only a
+If the content of the newly created FlowFile is to be only a
contiguous subset of the bytes of the original FlowFile, it is
preferred
to use the `clone(FlowFile, long, long)` method instead of the
