refactor: refactor bad smell UnnecessaryToStringCall (#186)

* Refactor bad smells:
- UnnecessaryToStringCall
The toString() method is not needed in cases the underlying method handles the conversion. Also calling toString() on a String is redundant. Removing them simplifies the code.

src/main/java/org/apache/maven/plugins/shade/filter/MinijarFilter.java

@@ -262,14 +262,13 @@ private ClazzpathUnit addDependencyToClasspath(Clazzpath cp, Artifact dependency
             log.warn(dependency.getFile()
                     + " could not be unpacked/read for minimization; dependency is probably malformed.");
             IOException ioe = new IOException(
-                    "Dependency " + dependency.toString() + " in file " + dependency.getFile()
+                    "Dependency " + dependency + " in file " + dependency.getFile()
                             + " could not be unpacked. File is probably corrupt",
                     e);
             throw ioe;
         } catch (ArrayIndexOutOfBoundsException | IllegalArgumentException e) {
             // trap ArrayIndexOutOfBoundsExceptions caused by malformed dependency classes (MSHADE-107)
-            log.warn(dependency.toString()
-                    + " could not be analyzed for minimization; dependency is probably malformed.");
+            log.warn(dependency + " could not be analyzed for minimization; dependency is probably malformed.");
         }
 
         return clazzpathUnit;