Update failing unit test

Author: michaeldavis-wf

src/test/java/io/swagger/codegen/v3/generators/java/AbstractJavaCodegenTest.java

@@ -95,7 +95,7 @@ public void convertVarName() throws Exception {
         Assert.assertEquals(fakeJavaCodegen.toVarName("user-name"), "userName");
         Assert.assertEquals(fakeJavaCodegen.toVarName("user_name"), "userName");
         Assert.assertEquals(fakeJavaCodegen.toVarName("_user_name"), "_userName");
-        Assert.assertEquals(fakeJavaCodegen.toVarName("@user_name"), "userName");
+        Assert.assertEquals(fakeJavaCodegen.toVarName(":user_name"), "userName");
     }
 
     @Test