Fixed bug in Pod in Changes file

Changes

@@ -1,27 +1,27 @@
 =head1 Math::GSL Changes
 
-=head v0.49 - July 2024
+=head1 v0.49 - July 2024
 
     - Fix Pod errors in Changes file
     - Add Git meta data to be used by the metacpan.org web site
 
-=head v0.48 - July 2024
+=head1 v0.48 - July 2024
 
     - Fix build failure for gcc 14 on debian (emollier)
 
-=head v0.47 - July 2024
+=head1 v0.47 - July 2024
 
     - Build shared libgsl.so by default. See https://github.com/PerlAlien/Alien-GSL/issues/17 for
       more information.
 
-=head v0.46 - July 2024
+=head1 v0.46 - July 2024
 
     - Fixes some test failures compared to version 0.45 released at metacpan.org: 
     - Linalg.t : "GSL LINALG LU DECOMP" returned 0 instead of 4
     - Matrix.so: undefined symbol: gsl_matrix_char_norm1 and gsl_spmatrix_char_norm1
     - Fixes wrong version number in Changes file
 
-=head v0.45 - July 2024
+=head1 v0.45 - July 2024
 
     - Added support for GSL 2.8 (hakonhagland)
     - Update to distribution metadata (mohawk2)