gumjs: Fix a stylistic inconsistency #1108

Job	Run time
freebsd-arm64	1m 54s
gir	2m 11s
android-arm (arm)	2m 41s
android-intel (x86)	9m 19s
android-arm (arm64)	3m 0s
android-intel (x86_64)	5m 44s
ios-arm64	1m 14s
linux-mips (mips, g++-mips-linux-gnu)	3m 15s
linux-x86	3m 4s
linux-mips (mipsel, g++-mipsel-linux-gnu)	1m 51s
linux-x86_64	2m 11s
macos-x86_64	4m 19s
linux-mips (mips64, g++-mips64-linux-gnuabi64)	1m 44s
linux-mips (mips64el, g++-mips64el-linux-gnuabi64)	1m 40s
qnx-armeabi	1m 39s
windows (amd64_x86)	4m 35s
windows (amd64)	4m 53s
	55m 14s

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