config.yaml 不设置 webhook 的时候，会一直报错 "panic: runtime error: invalid memory address or nil pointer dereference"

[w-rui]

由于不需要 webhook，所以未设置相关参数，导致运行的时候一直报错。填写一个虚假的就正常运行了。
建议即使未设置，流程也往下走，而不是卡住核心流程。

报错信息：

{"log":"2025/11/04 09:46:53 ERRO \u003cwebhook/webhook.go:63\u003e Post \"\": unsupported protocol scheme \"\"\n","stream":"stderr","time":"2025-11-04T01:46:53.15738083Z"}
{"log":"panic: runtime error: invalid memory address or nil pointer dereference\n","stream":"stderr","time":"2025-11-04T01:46:53.159723724Z"}
{"log":"[signal SIGSEGV: segmentation violation code=0x1 addr=0x10 pc=0x84ceb3]\n","stream":"stderr","time":"2025-11-04T01:46:53.159759162Z"}
{"log":"\n","stream":"stderr","time":"2025-11-04T01:46:53.159781162Z"}
{"log":"goroutine 28 [running]:\n","stream":"stderr","time":"2025-11-04T01:46:53.159792108Z"}
{"log":"github.com/nekoimi/oss-auto-cert/notifications/webhook.(*Notify).Notify.func1()\n","stream":"stderr","time":"2025-11-04T01:46:53.159795265Z"}
{"log":"\u0009/build/notifications/webhook/webhook.go:65 +0x293\n","stream":"stderr","time":"2025-11-04T01:46:53.159798382Z"}
{"log":"created by github.com/nekoimi/oss-auto-cert/notifications/webhook.(*Notify).Notify in goroutine 17\n","stream":"stderr","time":"2025-11-04T01:46:53.159801409Z"}
{"log":"\u0009/build/notifications/webhook/webhook.go:45 +0x74\n","stream":"stderr","time":"2025-11-04T01:46:53.159804401Z"}

[nekoimi]

已修复，可配可不配 #33

国内阿里云: registry.cn-hangzhou.aliyuncs.com/nekoimi/oss-auto-cert:latest