Add better warning message when debug with no script attached; #298

Job	Run time
📊 Static checks / Code style, file formatting, and docs	2m 34s
🤖 Android / Template (target=template_release)	28m 13s
🍏 iOS / Template (target=template_release)	17m 56s
🍎 macOS / Editor (target=editor, tests=yes)	25m 11s
🐧 Linux / Editor w/ Mono (target=editor)	34m 6s
🍎 macOS / Template (target=template_release)	30m 25s
🐧 Linux / Editor with doubles and GCC sanitizers (target=editor, tests=yes, dev_build=yes, scu_build=yes, precision=double, use_asan=yes, use_ubsan=yes, linker=gold)	37m 8s
🌐 Web / Template (target=template_release)	16m 2s
🏁 Windows / Editor (target=editor, tests=yes)	41m 42s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	30m 45s
🏁 Windows / Template (target=template_release)	29m 8s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	27m 47s
🐧 Linux / Template w/ Mono (target=template_release)	23m 18s
🐧 Linux / Minimal template (target=template_release, everything disabled)	15m 26s
🪲 Godot CPP / Build and test Godot CPP	6m 49s
	6h 6m 30s

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