errors: raise InputError on early parse error in dispatch

I didn't think this would have any effect on the tests, but it does
because the catching in `scmutil.callcatch()` still happens. That's
because `dispatch` passes in the function that includes the parsing as
an argument to that function.

I initially used `ConfigError` here but Matt Harbison convinced me to
use `InputError`. I think that makes sense since error is not in a
config file.

Differential Revision: https://phab.mercurial-scm.org/D9387

mercurial/dispatch.py

@@ -849,7 +849,7 b' def _parseconfig(ui, config):'
             ui.setconfig(section, name, value, b'--config')
             configs.append((section, name, value))
         except (IndexError, ValueError):
-            raise error.Abort(
+            raise error.InputError(
                 _(
                     b'malformed --config option: %r '
                     b'(use --config section.name=value)'

tests/test-globalopts.t

@@ -217,19 +217,19 b' Testing --config:'
   quuxfoo
   $ hg --cwd c --config '' tip -q
   abort: malformed --config option: '' (use --config section.name=value)
-  [255]
+  [10]
   $ hg --cwd c --config a.b tip -q
   abort: malformed --config option: 'a.b' (use --config section.name=value)
-  [255]
+  [10]
   $ hg --cwd c --config a tip -q
   abort: malformed --config option: 'a' (use --config section.name=value)
-  [255]
+  [10]
   $ hg --cwd c --config a.= tip -q
   abort: malformed --config option: 'a.=' (use --config section.name=value)
-  [255]
+  [10]
   $ hg --cwd c --config .b= tip -q
   abort: malformed --config option: '.b=' (use --config section.name=value)
-  [255]
+  [10]
 
 Testing --debug: