Fixed a issue that cause bot initialization failed on headless platform

mirai-core/src/jvmMain/kotlin/net/mamoe/mirai/utils/BotConfigurationJvm.kt

@@ -49,12 +49,16 @@ class DefaultLoginSolver(
             }
 
             tempFile.inputStream().use {
+                try {
                     val img = ImageIO.read(it)
                     if (img == null) {
                         logger.info("无法创建字符图片. 请查看文件")
                     } else {
                         logger.info(img.createCharImg())
                     }
+                } catch (throwable: Throwable) {
+                    logger.info("创建字符图片时出错(${throwable.toString()})。请查看文件")
+                }
             }
         }
         logger.info("请输入 4 位字母验证码. 若要更换验证码, 请直接回车")