remove sussy NBSP from test case

Author: KotlinIsland

test-data/unit/check-flags.test

@@ -1991,7 +1991,7 @@ x.trim()  # E: "str" has no attribute "trim"  [attr-defined]
 [case testEnableDifferentErrorCode]
 # flags: --disable-error-code attr-defined --enable-error-code name-defined --show-error-code
 x = 'should not be fine'
-x.trim()  # E: "str" has no attribute "trim"  [attr-defined]
+x.trim()  # E: "str" has no attribute "trim"  [attr-defined]
 
 [case testEnableMultipleErrorCode]
 # flags: \