Revert "Reorganize earlyinit checks"

This reverts commit 6f3f9ede01a6b30b105d5110a48cfea592e8db52.

qutebrowser/misc/earlyinit.py

@@ -322,7 +322,8 @@ def check_libraries(backend):
     if backend == 'webengine':
         modules['PyQt5.QtWebEngineWidgets'] = _missing_str("QtWebEngine",
                                                            webengine=True)
-    elif backend == 'webkit':
+    else:
+        assert backend == 'webkit'
         modules['PyQt5.QtWebKit'] = _missing_str("PyQt5.QtWebKit")
         modules['PyQt5.QtWebKitWidgets'] = _missing_str(
             "PyQt5.QtWebKitWidgets")
@@ -406,15 +407,10 @@ def earlyinit(args):
     fix_harfbuzz(args)
     # Now we can be sure QtCore is available, so we can print dialogs on
     # errors, so people only using the GUI notice them as well.
-    #
-    # First do some early version checks, without knowing the backend.
-    check_qt_version(None)
-    remove_inputhook()
-    check_libraries(None)
-    check_ssl_support()
-    check_optimize_flag()
-    # Now find out the backend to use, and do the rest of the checks
     backend = get_backend(args)
     check_qt_version(backend)
+    remove_inputhook()
     check_libraries(backend)
+    check_ssl_support()
+    check_optimize_flag()
     set_backend(backend)