Readme update

README.md

@@ -1,4 +1,4 @@
-© Ihor Mirzov, January 2020  
+© Ihor Mirzov, May 2020  
 Distributed under GNU General Public License v3.0
 
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@@ -25,6 +25,8 @@ Converts [Salome](https://www.salome-platform.org/) .unv file to [CalculiX](http
 
 This converter is based on Joël's Cugnoni UNV parser available with [CalculiX Launcher](http://www.calculixforwin.com/) distribution. I allowed myself to slightely improve it and translate into Python 3. INPWriter's methods are fully refactored and now allow to convert beams. See folder [tests](./tests) for list of tested UNV elements. All generated INP files are processed by CalculiX GraphiX and [CalculiX CAE](https://github.com/calculix/cae) without any errors.
 
+Thanks to [Niclas Stenberg](https://github.com/Xnst) for fixing bug with empty sets.
+
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@@ -80,4 +82,4 @@ Please, you may:
 Create binary with [pyinstaller](https://www.pyinstaller.org/) (both in Linux and in Windows):
 
     pip3 install pyinstaller
-    pyinstaller unv2ccx.py --onefile
+    pyinstaller unv2ccx.py --onefile