fixed typo in usage

src/trim_paired.c

@@ -42,7 +42,7 @@ void paired_usage(int status) {
             PROGRAM_NAME);
     fprintf(stderr, "\nIf you have one file with interleaved forward and reverse reads...\n");
     fprintf(stderr, "\nUsage: %s pe -c <combined input file> -t <quality type> -m <combined trimmed output> -s <trimmed singles file>\n", PROGRAM_NAME);
-    fprintf(stderr, "\n Options:\n\
+    fprintf(stderr, "\nOptions:\n\
 -t, --qual-type, Type of quality values (solexa (CASAVA < 1.3), illumina (CASAVA 1.3 to 1.7), sanger (which is CASAVA >= 1.8)) (required)\n\
 -f, --pe-file1, Input paired-end fastq file 1 (optional, must have same number of records as pe2)\n\
 -r, --pe-file2, Input paired-end fastq file 2 (optional, must have same number of records as pe1)\n\