Bugfix: StringMap.put() returns void; updating the rule accordingly.

Author: marek-trtik

benchmarks/TRAINING/diffblue/taint_traces_05_rules.json

@@ -101,7 +101,7 @@
         "comment": "Inserting a potentially tainted string into a StringMap container. Making the container tainted.",
         "id": "StringMap.put(*,String)->*",
         "class": "StringMap",
-        "method": "put:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;",
+        "method": "put:(Ljava/lang/Object;Ljava/lang/String;)V",
         "input": {
           "location": "arg2",
           "taint": "<toString(TaintedInputStream.read@byte[])@String>"