fix: use proper exception chaining with 'raise from' in glogging.py

Use 'raise X from e' syntax instead of just 'raise X' when wrapping
exceptions. This provides more accurate exception chaining messages
("The above exception was the direct cause of" vs "During handling of").

Closes #2360

gunicorn/glogging.py

@@ -237,7 +237,7 @@ class Logger:
                     ValueError,
                     TypeError
             ) as exc:
-                raise RuntimeError(str(exc))
+                raise RuntimeError(str(exc)) from exc
         elif cfg.logconfig_json:
             config = CONFIG_DEFAULTS.copy()
             if os.path.exists(cfg.logconfig_json):
@@ -252,7 +252,7 @@ class Logger:
                     ValueError,
                     TypeError
                 ) as exc:
-                    raise RuntimeError(str(exc))
+                    raise RuntimeError(str(exc)) from exc
         elif cfg.logconfig:
             if os.path.exists(cfg.logconfig):
                 defaults = CONFIG_DEFAULTS.copy()
@@ -442,8 +442,8 @@ class Logger:
         # syslog facility
         try:
             facility = SYSLOG_FACILITIES[cfg.syslog_facility.lower()]
-        except KeyError:
-            raise RuntimeError("unknown facility name")
+        except KeyError as exc:
+            raise RuntimeError("unknown facility name") from exc
 
         # parse syslog address
         socktype, addr = parse_syslog_address(cfg.syslog_addr)