Update repositories.txt

https://github.com/closedcube/ is dead

I found and fix error in this library. 
I worked on other fork of library.

Author: malarz-supla

repositories.txt

@@ -1671,7 +1671,7 @@ https://github.com/closedcube/ClosedCube_LPS25HB_Arduino
 https://github.com/closedcube/ClosedCube_MAX30205_Arduino
 https://github.com/closedcube/ClosedCube_OPT3001_Arduino
 https://github.com/closedcube/ClosedCube_OPT3002_Arduino
-https://github.com/closedcube/ClosedCube_SHT31D_Arduino
+https://github.com/malarz-supla/ClosedCube_SHT31D_Arduino
 https://github.com/closedcube/ClosedCube_SHT3XA_Library
 https://github.com/closedcube/ClosedCube_SHT3XD_Library
 https://github.com/closedcube/ClosedCube_SHTC3_Arduino