Make the 'silent or' test case not fail when it should

Previously it would have failed in two different ways depending on whether the parser bug was fixed. Now it will only fail if the parser bug is fixed.

test cases/failing/55 or on new line/meson.build

@@ -1,13 +1,7 @@
 project('silent_or', 'c')
 
-if get_option('foo') == 'true' or get_option('foo') == 'auto'
-
-else
-        error('This case is fine - this error isn't triggered.')
-endif
-
 if get_option('foo') == 'true'
         or get_option('foo') == 'auto'
 else
-        error('This error is triggered because the or statement is silently ignored.')
+        message('If this message is printed then something is wrong. The or above should give a syntax error.')
 endif