change bcftools image name

tools/bcftools_vcfFile_stats/bcftools_vcfFile_stats.yaml

@@ -36,7 +36,7 @@
             {
               name: "stats_image",
               type: "png",
-              file: "stats_mqc.png",
+              file: "bcftools_stats_mqc.png",
               description: "VCF file stats graphs",
             }
           ],