removed extra blank lines

Author: Marie BONBOIRE

src/sage/matrix/matrix_space.py

@@ -1805,7 +1805,6 @@ def identity_matrix(self):
         if self.__nrows != self.__ncols:
             raise TypeError("identity matrix must be square")
         A = self.zero_matrix().__copy__()
-        
         for i in range(self.__nrows):
             A[i, i] = 1
         A.set_immutable()
@@ -1865,7 +1864,6 @@ def diagonal_matrix(self, entries):
         if self.__nrows < len(entries):
             raise ValueError('number of diagonal matrix entries (%s) exceeds the matrix size (%s)' % (len(entries), self.__nrows))
         A = self.zero_matrix().__copy__()
-        
         for i in range(len(entries)):
             A[i, i] = entries[i]
         return A