[balsa] gmime-gpgme-signature: Fix the build

[Peter Bloomfield <peterb src gnome org>]

commit fc8b695c50dd0700f082b79ca5682836c632ac33
Author: Peter Bloomfield <PeterBloomfield bellsouth net>
Date:   Wed Jun 12 19:34:02 2019 -0400

    gmime-gpgme-signature: Fix the build
    
    gpgme-signature: Build with -Wignored-qualifiers
    
    libbalsa/gmime-gpgme-signature.[ch]: In
    "const gpgme_key_t g_mime_gpgme_sigstat_key(…)", the "const" qualifier is
    ignored; drop it.
    
    Because gpgme_key_t is defined by
    
    typedef struct _gpgme_key *gpgme_key_t;
    
    it cannot be usefully constified. If it had been defined by
    
    typedef struct _gpgme_key gpgme_key_t;
    
    then "const gpgme_key_t *key" would have given read-only access to the
    key. But as it is, "const gpgme_key_t key" defines a variable to which
    no key can be assigned!

 libbalsa/gmime-gpgme-signature.c | 2 +-
 libbalsa/gmime-gpgme-signature.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/libbalsa/gmime-gpgme-signature.c b/libbalsa/gmime-gpgme-signature.c
index 7fa015169..748a7f078 100644
--- a/libbalsa/gmime-gpgme-signature.c
+++ b/libbalsa/gmime-gpgme-signature.c
@@ -270,7 +270,7 @@ g_mime_gpgme_sigstat_summary(GMimeGpgmeSigstat *sigstat)
 }
 
 
-const gpgme_key_t
+gpgme_key_t
 g_mime_gpgme_sigstat_key(GMimeGpgmeSigstat *sigstat)
 {
        g_return_val_if_fail(GMIME_IS_GPGME_SIGSTAT(sigstat), NULL);
diff --git a/libbalsa/gmime-gpgme-signature.h b/libbalsa/gmime-gpgme-signature.h
index 5839cfc2a..5232799ae 100644
--- a/libbalsa/gmime-gpgme-signature.h
+++ b/libbalsa/gmime-gpgme-signature.h
@@ -49,7 +49,7 @@ gchar *g_mime_gpgme_sigstat_signer(GMimeGpgmeSigstat *sigstat)
 gpgme_protocol_t g_mime_gpgme_sigstat_protocol(GMimeGpgmeSigstat *sigstat);
 gpgme_error_t g_mime_gpgme_sigstat_status(GMimeGpgmeSigstat *sigstat);
 gpgme_sigsum_t g_mime_gpgme_sigstat_summary(GMimeGpgmeSigstat *sigstat);
-const gpgme_key_t g_mime_gpgme_sigstat_key(GMimeGpgmeSigstat *sigstat);
+gpgme_key_t g_mime_gpgme_sigstat_key(GMimeGpgmeSigstat *sigstat);
 const gchar *g_mime_gpgme_sigstat_fingerprint(GMimeGpgmeSigstat *sigstat);
 
 gchar *libbalsa_cert_subject_readable(const gchar *subject)