base: Use repr() for printing exceptions

Exceptions print more clearly using repr() instead of str(), fix
in fetch and unpack tasks.

Drop part of the test which no longer makes sense after this change.

(From OE-Core rev: c94816259cc1c09746353ad26ca0c811e0c962c2)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/base.bbclass

@@ -160,7 +160,7 @@ python base_do_fetch() {
         fetcher = bb.fetch2.Fetch(src_uri, d)
         fetcher.download()
     except bb.fetch2.BBFetchException as e:
-        bb.fatal(str(e))
+        bb.fatal("Bitbake Fetcher Error: " + repr(e))
 }
 
 addtask unpack after do_fetch
@@ -177,7 +177,7 @@ python base_do_unpack() {
         fetcher = bb.fetch2.Fetch(src_uri, d)
         fetcher.unpack(d.getVar('WORKDIR'))
     except bb.fetch2.BBFetchException as e:
-        bb.fatal(str(e))
+        bb.fatal("Bitbake Fetcher Error: " + repr(e))
 }
 
 def get_layers_branch_rev(d):