SPATIAL INDEX should not be allowed for FOREIGN KEY

Bug#27912873 CRASH: SEGMENTATION FAULT IN HA_INNOBASE::INDEX_TYPE() blocks SPATIAL INDEX from being considered for FOREIGN KEY. No test case was included, and I was unable to come up with one that would not reject the FOREIGN KEY.

That said, the function dict_foreign_qualify_index() should reject both FULLTEXT INDEX and SPATIAL INDEX, and its callers should not check for these.