it's safe to negate expression in !EXP only in boolean context

#kendo

lib/compress.js

@@ -1446,10 +1446,10 @@ merge(Compressor.prototype, {
                 compressor.warn("Boolean expression always true [{file}:{line},{col}]", self.start);
                 return make_node(AST_True, self);
             }
-        }
             if (e instanceof AST_Binary && self.operator == "!") {
                 self = best_of(self, e.negate(compressor));
             }
+        }
         return self.evaluate(compressor)[0];
     });