-rc2: because pypi won't accept -rc1

RELEASE_NOTES.rst

@@ -5,7 +5,7 @@ Please always read this file before installing the package
 
 Download software here: https://github.com/fritz-hh/OCRmyPDF/tags
 
-v3.0-rc1:
+v3.0-rc2:
 =========
 
 New features

ocrmypdf/main.py

@@ -75,7 +75,7 @@ if tesseract.version() < MINIMUM_TESS_VERSION:
 parser = cmdline.get_argparse(
     prog="ocrmypdf",
     description="Generate searchable PDF file from an image-only PDF file.",
-    version='3.0rc1',
+    version='3.0rc2',
     fromfile_prefix_chars='@',
     ignored_args=[
         'touch_files_only', 'recreate_database', 'checksum_file_name',

setup.py

@@ -169,7 +169,7 @@ if command.startswith('install') or \
 
 setup(
     name='ocrmypdf',
-    version='3.0rc1',
+    version='3.0rc2',
     description='OCRmyPDF adds an OCR text layer to scanned PDF files, allowing them to be searched',
     url='https://github.com/fritz-hh/OCRmyPDF',
     author='J. R. Barlow',