Update README.md (trekhleb#332)

nirvanarsc · trekhleb · commit d790aa56a491 · 2019-04-12T08:41:26.000+03:00
Fix for trekhleb#311
diff --git a/src/algorithms/string/levenshtein-distance/README.md b/src/algorithms/string/levenshtein-distance/README.md
@@ -106,7 +106,7 @@ bottom-up direction) is being applied here.
 Applying this principle further we may solve more complicated cases like 
 with `Saturday → Sunday` transformation.
 
-![Levenshtein distance](https://cdn-images-1.medium.com/max/1600/1*geMdmZcdU1bZbHIoh6KO3Q.png)
+![Levenshtein distance](https://user-images.githubusercontent.com/1153337/54865681-9457b380-4dac-11e9-959a-01c8ca00a85f.png)
 
 ## References
 
