Fix screen center position returned for rotated Camera2D #92

Job	Run time
📊 Static checks / Code style, file formatting, and docs	3m 47s
🤖 Android / Template (target=template_release)	43m 17s
🍎 macOS / Editor (target=editor, tests=yes)	42m 40s
🍏 iOS / Template (target=template_release)	23m 53s
🐧 Linux / Editor w/ Mono (target=editor)	1h 7m 4s
🌐 Web / Template (target=template_release)	39m 48s
🍎 macOS / Template (target=template_release)	32m 17s
🐧 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)	57m 50s
🏁 Windows / Editor (target=editor, tests=yes)	1h 6m 58s
🏁 Windows / Template (target=template_release)	48m 24s
🐧 Linux / Editor with clang sanitizers (target=editor, tests=yes, dev_build=yes, use_asan=yes, use_ubsan=yes, use_llvm=yes, linker=lld)	47m 26s
🐧 Linux / Editor with ThreadSanitizer (target=editor, tests=yes, dev_build=yes, use_tsan=yes, use_llvm=yes, linker=lld)	52m 55s
🐧 Linux / Template w/ Mono (target=template_release)	35m 13s
🐧 Linux / Minimal template (target=template_release, everything disabled)	20m 12s
🪲 Godot CPP / Build and test Godot CPP	9m 33s
	9h 51m 17s

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