Fix config loading in some edge cases

Fixes #999

Usually where try/except wouldn't catch NoOptionError, happens when running tests in specific environments.

sopel/config/__init__.py

@@ -70,10 +70,8 @@ def homedir(self):
         # Technically it's the other way around, so we can bootstrap filename
         # attributes in the core section, but whatever.
         configured = None
-        try:
+        if self.parser.has_option('core', 'homedir'):
             configured = self.parser.get('core', 'homedir')
-        except ConfigParser.NoOptionError:
-            pass
         if configured:
             return configured
         else:

sopel/config/types.py

@@ -143,9 +143,9 @@ def __get__(self, instance, owner=None):
             # instance here.
             return self
 
-        try:
+        if instance._parser.has_option(instance._section_name, self.name):
             value = instance._parser.get(instance._section_name, self.name)
-        except configparser.NoOptionError:
+        else:
             if self.default is not NO_DEFAULT:
                 return self.default
             raise AttributeError(
@@ -290,9 +290,9 @@ def __init__(self, name, relative=True, directory=False, default=None):
     def __get__(self, instance, owner=None):
         if instance is None:
             return self
-        try:
+        if instance._parser.has_option(instance._section_name, self.name):
             value = instance._parser.get(instance._section_name, self.name)
-        except configparser.NoOptionError:
+        else:
             if self.default is not NO_DEFAULT:
                 value = self.default
             else: