Prior to this commit, the addDefaultHttpMessageConverters() method in
WebMvcConfigurationSupport caught Throwable for SourceHttpMessageConverter
instantiation; whereas, the rest of the code base correctly catches Error
for SourceHttpMessageConverter instantiation (to handle errors such as
NoClassDefFoundError).
Throwable should not be caught since it can mask other categories of
failures (such as configuration errors).
This commit therefore switches to catching Error for SourceHttpMessageConverter
instantiation in WebMvcConfigurationSupport.
Closes gh-29537
72b44cebea