Silence some warnings.

src/fmail.c

@@ -29,6 +29,7 @@
 #include <time.h>
 #include <unistd.h>
 #include <sys/stat.h>
+#include <err.h>
 
 #include <gpgme.h>
 #include <magic.h>
@@ -121,7 +122,7 @@ typedef struct fmail_ctx
 static char *
 generate_boundary(char *buffer, size_t len)
 {
-    int i;
+    unsigned i;
 
     for ( i = 0; i < len - 1; i++ )
         buffer[i] = base64_chars[rand() % (sizeof(base64_chars) - 1)];
@@ -258,7 +259,7 @@ static void
 process_text_body(fmail_ctx_t *ctx, FILE *out)
 {
     char boundary[32];
-    int i;
+    unsigned i;
 
     if ( ctx->att_count > 0 ) {
         generate_boundary(boundary, sizeof(boundary));
@@ -356,7 +357,6 @@ sign_stream(gpgme_ctx_t ctx, FILE *in, FILE *out)
 
     gpgme_op_sign(ctx, gin, gout, GPGME_SIG_MODE_DETACH);
     result = gpgme_op_sign_result(ctx);
-    result->signatures->hash_algo;
 
     generate_boundary(boundary, sizeof(boundary));
     fprintf(out, "Content-Type: multipart/signed;\r\n"