fix OSSL_STORE man pages

the man pages have lines that contain nothing but whitespace,
clean it up by removing that whitespace

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1334)
diff --git a/doc/man3/OSSL_STORE_LOADER.pod b/doc/man3/OSSL_STORE_LOADER.pod
index 4386c28..6a6d3b6 100644
--- a/doc/man3/OSSL_STORE_LOADER.pod
+++ b/doc/man3/OSSL_STORE_LOADER.pod
@@ -52,7 +52,7 @@
  int OSSL_STORE_LOADER_set_close(OSSL_STORE_LOADER *store_loader,
                                  OSSL_STORE_close_fn store_close_function);
  void OSSL_STORE_LOADER_free(OSSL_STORE_LOADER *store_loader);
- 
+
  int OSSL_STORE_register_loader(OSSL_STORE_LOADER *loader);
  OSSL_STORE_LOADER *OSSL_STORE_unregister_loader(const char *scheme);