optimize:optimization of seata-spring-boot-starter

[xingfudeshi]

Ⅰ. Describe what this PR did

1.remove @ConditionalOnClass(DataSourceProxy.class)
2.add attribute havingValue = "true" in @ConditionalOnProperty

Ⅱ. Does this pull request fix one issue?

Ⅲ. Why don't you add test cases (unit test/integration test)?

I've done integration testing.

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #1867 into develop will decrease coverage by 0.1%.
The diff coverage is n/a.

@@              Coverage Diff              @@
##             develop    #1867      +/-   ##
=============================================
- Coverage      55.34%   55.24%   -0.11%     
  Complexity      2376     2376              
=============================================
  Files            422      422              
  Lines          14314    14286      -28     
  Branches        1716     1676      -40     
=============================================
- Hits            7922     7892      -30     
+ Misses          5655     5646       -9     
- Partials         737      748      +11

Impacted Files	Coverage Δ	Complexity Δ
...obuf/convertor/BranchRegisterRequestConvertor.java	88% <0%> (-8%)	3% <0%> (ø)
...buf/convertor/GlobalLockQueryRequestConvertor.java	92.59% <0%> (-7.41%)	3% <0%> (ø)
...otobuf/convertor/GlobalStatusRequestConvertor.java	94.73% <0%> (-5.27%)	3% <0%> (ø)
...obuf/convertor/GlobalRollbackRequestConvertor.java	94.73% <0%> (-5.27%)	3% <0%> (ø)
...otobuf/convertor/GlobalCommitRequestConvertor.java	94.73% <0%> (-5.27%)	3% <0%> (ø)
...protobuf/convertor/RegisterTMRequestConvertor.java	95.45% <0%> (-4.55%)	3% <0%> (ø)
...protobuf/convertor/RegisterRMRequestConvertor.java	91.66% <0%> (-4.17%)	3% <0%> (ø)
...otobuf/convertor/BranchReportRequestConvertor.java	92.59% <0%> (-3.71%)	3% <0%> (ø)
...rotobuf/convertor/RegisterTMResponseConvertor.java	81.25% <0%> (-3.6%)	3% <0%> (ø)
...rotobuf/convertor/RegisterRMResponseConvertor.java	81.25% <0%> (-3.6%)	3% <0%> (ø)
... and 18 more

[slievrly]

LGTM

[zjinlei]

LGTM